To be fair I have never had an issue with sony support as far as I am aware SE is the one who ties the game directly to the the PSN account and they not sony are the ones who have to unlink it. For SE support in the A Realm Reborn support area here:
https://support.na.square-enix.com/c...p?id=5382&la=1 choose accounts/ID then select registration code, type anything for the reason like wrong PSN. After that click next.
It will ask you to log in do so.
It will then ask for your prefered method of contact, proceed with your choice fill out the form then use the method of contact that they supply the information to. Outside of that I dont think anything can be done.