Legal CS6 educational version got revoked, is it safe to purchase subscription on cs chatboard?

I would like to know if there is another user's CS6 serial number has been invoked because of using it in different region. And is it safe to purchase the subscription with the customer service on chatboard?

I was a student in an Adobe authorized IT school to study CS6 design and creative suite for building website at 2012 in East Asia Pacific area. I got the Adobe's offical certificate from this school after studying this expensive course. As it is an authorized school partnering with Adobe, they offered a legal version of CS6 free of charge (of course the price has been added in the course fee) for every student.  We needed to submit our proof of study as a student for this school to East Asia Pacific Adobe and claim a serial number for this education CS6 version from Adobe. I have no reason to question this school will buy their copy from illegal way as they are partnering with Adobe to provide course for over 15 years now, even nowaday they are still providing courses for up to date creative cloud version. 

5 days ago I suddenly got a pop up on my desktop,  without a close button,  said my serial number is invalid and will not be able to use in 5 days. I think i got hacked. I checked my anti-virus software (legal purchased version), it said my computer is fine. So when next day I saw the same pop up but the count down said 4 days left, I take my chance to click the learn more button on that pop up.  Then it linked to Adobe. 

I contacted customer service and want to know which software has this serial number problem,  as I know all my software is a legal purchased and legal copy. At that time I still think is it some hacker get to my computer and cause that problem. But after I talked with them, they told me my serial number is invoked. 

I asked the reason. They said it maybe the school bought those education version in a illegal reseller. I said it is impossible. They asked me to provide the invoice,  which is my class' invoice in a paper format 12 years ago. They knew I won't be able to give them an invoice so said they can't do anything about it and ask me to purchase the subscription version instead.

I had the long distance call with school that night and they said it is impossible the copy has problem.  And if I need a reprint record,  they are happy to provide it if I can bring my ID and a reprint fee to them. I don't blame them charge me as it is a 12 years ago record, I'm lucky they still have my school record. 

Before I paid that, I want to make sure if I provide the invoice can I really get my legal version CS6 back. I also look up my old emails, I found out the serial number was provided by Adobe. So I contacted customer service again.

This time they said even I can provide the invoice,  I won't be able to use it. Their new reason is, my school copy is East Asia Pacific region version,  I can't use it in USA.  

Lucky I didn't pay for reprint that invoice yet....and they keep asking me to provide billing address to purchase the subscription version.  

I didn't have my installation package with me anymore.  I downloaded the installation files from adobe website when I bought a new computer in USA, and with the help from Adobe support, they help me install it on my window 10 new computer.  So the installer file are provided by Adobe as well. That was around 4 years ago, no one told me I can't use it in USA. 

And suddenly,  just 5 days notification,  I can't use my legal copy again. No one let me know I can't use it in USA, no warning at all. As a school copy, who will ask the school if I can use this software oversea? It is an super old product,  no updates, but good fit for my hobby use. It supposed to be a lifetime product if your computer still supports it. Well, I have to no way to proof they have small prints on limitation for region use,  just I can just trust their words they said it is a region limited version.  They even didn't let me keep this software to use in East Asia Pacific region. Just invoked the serial number that Adobe east Asia Pacific  gave me. No refund at all. My friends told me I should look for a lawyer. 

I want to say, I'm really disappointed on this big company 😔 I always bought legal version software for my computer. Adobe subscription is good for commercial use to keep all things up-to-date,  but for us these old school home users? Cs6 is our last version that can buy off to use on our own time, their simple functions are good enough for our home use. We don't use it daily but with the subscription,  we need to pay daily.  Soon or later all the Adobe user will become commercial user only, as that is the price that only a company can afford it. We can't have a tax deductible for this software but a company can do it. As a hobby, it is an expensive hobby.

Can Adobe release one version that we can buy off for lifetime again? Like Microsoft Office after they found out the 360 version makes them lost a lot of customers,  they released a home and student use version,  no need to pay subscription.  

Right now if I want to keep my simple website updating,  I need to purchase the subscription. I already paid for my hosting for this year,  so before i found other replacement software,  i need Photoshop and Dreamweaver.  Is it safe to purchase it by customer service? They keep asking me give them the billing address on the chat board...