Binding account

When I try to bind my account, I get the email, but when I go to put the code in an old email I don't have access to anymore is there. After a day or 2 it is back to a blank. So I try again. The game again sends the email, when I type okay, so I can enter the code, it again says it is bound to this old address. I have tried gree support and gotten the basic how to bind account instructions. This is my second account, and I will want to replace this tablet soon. Thanks for any help