My email is no longer connected to my Lightroom 6 serial number

Hello.. I was trying to install a copy of Lightroom 6 to a new computer and got the message that I had to deactivate some copies.  I went to my account and Lightroom 6 was wiped from my list of apps.  I called tech support and they told me that my email was no longer tied to the serial number and they couldn't tell me which email was.  I told them that I bought Lightroom 6 new and use it almost every day for years and that it's my copy and serial number. I asked how it's possible that someone else's email is tied to my serial number and they replied "Maybe you sold it1" (LOL). I looked online about selling a license and it said that in order to sell a license both seller and buyer have to fill out a form and submit it to Adobe. That never happened(or at least I never filled out a form), so the license has been stolen from me. Who do I contact(do they have a security department?) to find out how my license was transferred without my permission and how I get it back... thanks! David