Cannot restore my subscription (despite having bought it)

My account is said to be already active when I try to use the partner offer. After putting my phone number where asked, no SMS is sent to me, instead,  a message saying my account is already active shows up with an option to log in to my account, but the button sends me to an error page and then to the app store. My progress ends there, as my account stays inactive. I’d like if someone helped restore my subscription. The same problem has already happened before and as it seems wasn’t fixed.