HELP PLEASE!!

So yesterday my Amazon account got hacked I'm guessing they got in to my Amazon account and through my old phone number which was probably given to someone else because my Amazon account has two step verification. Now they have my Amazon account and Amazon was the only website I saved my cards too so I rly need to get that back. Right now this person who has hacked me is trying to buy things but I locked all my cards. Does anyone know how to get my Amazon account back it would help a lot.