Problem with my apple ID

Hello

I was using my Apple Id smoothly, then a problem with facturation was saying me to have a new payment method, then I put another card, and it rejected again, later I tried to change Apple Id from App store because I really needed to update Clash of Clans in order to play when i putted, it told me it was already in use. Later I created a new Apple Id in order to update Clash of Clans. Later a message came to my email, saying that I changed the Apple Id and username, but I dont know what happened, now im scared because I have bought many thing with that Apple Id account

Help

Please