PS3 registration issue

Okay it is a lot more complicated than just the title but that is my main issue right now. I'll throw in the whole story and hope that helps make some sense of this mess I am trying to handle (kind of at my wits end here..).

SO, to start I had originally bought the ps3 standard edition on the PS store and apparently the graphics were so intense my poor old ps3 couldn't handle it (basically to the point pixels were shooting off into space and single textures were taking up the whole screen) so before it killed my ps3 I upgraded to the ps4 version since it was an option and free. I played on the ps4 fine for a while before my free trial was up and then I left it until now where I would like to play the ps3 version again so me and my boyfriend can play together since he is playing on our ps4. Here is where the frustration starts. After much research and many somewhat helpful chat supports with square, FFXIV support & PS store I was given the conclusion that if I wanted to play again I would need to rebuy the ps3 version. Well since I had originally bought the version digitally apparently I could not rebuy it or just buy the collectors edition on the store (no idea why still) so after a ridiculously hard search I was finally able to find a singular new copy a gamestop near by had found in the back. Now from what I was told by most the support people was that redeeming the product code on the ps3 should allow me to log in and pick which service account I would like my game to link with. Welp after registering, redownloading, reinstalling and registering on the square enix site I am still getting the message that says "Not valid service account is available to play." It says I need to transfer to regular service, purchase and enter a registration code and use that but seeing as I have done both I am at a loss what I am doing wrong now..

I have contacted final fantasy support and they told me to contact sony and see if their registration is connecting properly. After calling Sony because their chat support has blocked me (apparently I have been trying to contact them too much) the guy on the phone said this is not possible at all and I can not play the game on the ps3 again. This is just lovely.