Hi. I'm new to the forum, so I hope this is the right place to put this thread 
Anyways, I've been having an issue with the Play Store all day, trying to sort it out to no avail. I'm using an international Galaxy S III i9300.
Earlier, I tried to download a paid app, and I couldn't. I got an error saying something about my Visa, which is registered to my account, was invalid. I went to my Google Wallet page on my laptop, and removed my card, then tried to add it again. I couldn't. When I try to add it from my PC, I just get an error saying my card could not be validated. When I try to add it through the Play Store app, I get error rpc:s-7:AEC-0 .
Funny thing is, I tried adding my dads Visa on my account. Same error, both on phone and PC. However, when he tried to add his own card to his google account, it worked just fine. That leads me to believe that there is no problem with my card, but with my account somehow (my card has also been used on other online stores and at the local grocery store today, so I know it works.)
I've tried a lot of fixes I found online, mostly what pops up is error rpc:s-5:AEC-0 (notice the 5 instead of my error, which has a 7). The fixes involve clearing data/cache from Play Store, Google Services Framework etc, and removing and readding the google account itself on the phone. Nothing seems to be working.
I've emailed Google Wallet support earlier, but haven't got any response yet.
Apologies for a long-winded post, but I want to give you as much info as I can. Anyone experienced a similar situation before, anyone know how to fix this?
Thanks!

Anyways, I've been having an issue with the Play Store all day, trying to sort it out to no avail. I'm using an international Galaxy S III i9300.
Earlier, I tried to download a paid app, and I couldn't. I got an error saying something about my Visa, which is registered to my account, was invalid. I went to my Google Wallet page on my laptop, and removed my card, then tried to add it again. I couldn't. When I try to add it from my PC, I just get an error saying my card could not be validated. When I try to add it through the Play Store app, I get error rpc:s-7:AEC-0 .
Funny thing is, I tried adding my dads Visa on my account. Same error, both on phone and PC. However, when he tried to add his own card to his google account, it worked just fine. That leads me to believe that there is no problem with my card, but with my account somehow (my card has also been used on other online stores and at the local grocery store today, so I know it works.)
I've tried a lot of fixes I found online, mostly what pops up is error rpc:s-5:AEC-0 (notice the 5 instead of my error, which has a 7). The fixes involve clearing data/cache from Play Store, Google Services Framework etc, and removing and readding the google account itself on the phone. Nothing seems to be working.
I've emailed Google Wallet support earlier, but haven't got any response yet.
Apologies for a long-winded post, but I want to give you as much info as I can. Anyone experienced a similar situation before, anyone know how to fix this?
Thanks!

Thanks for all your help though!