Am i being taken advantage of by adobe?

Hello,

About a month ago i took out a subscription to adobe. When speaking with the sales assistant on chat, i specified i need adobe photoshop and that i need to be able to use older versions of adobe photshop, specifically cc 2018.  They told me the 'Photography Plan 20gb' will work and gave me what i thought was a good offer for it, so i went ahead.  for a month everything worked great, but have now found photoshop cc 2018 wont work; i go to load it and it asks me to log into my adobe cc account , but then bounces back that no account can be found for it, but if i try photoshop cc 2021 it works.  I was told my operating system needs updating and was provided a link to what requirements i need to have it working: ( https://helpx.adobe.com/uk/photoshop/system-requirements/earlier-versions.html#sa_src=web-messaging )  , upon reading this my systems meets all requirements.  As a tester I did 2 things, 1) It offered me a free trial period and i got photoshop cc 2018 working for seven days and then after this, i took out another subscription (on top of my photography 20gb plan ), the stand alone photoshop 100gb plan and then 2018 cc started working again also.  The clear issue being i now have two plans running. I tried speaking with them to see if they could move my terms and conditions to this new photoshop plan but seems i will be paying 3 times as much, for something i had working on my current plan and was told would work on the plan i originally took out.  This doesnt seem fair or right.