I can't speak for using AWS, but Amazon customer support in general is awful. Recently, my girlfriend was unable to get into her account. When she would try, it would say she had the wrong password. When she would try to reset the password, it would say the account didn't exist. When she gave up and just tried to recreate the account it wouldn't let her because it said the account already existed. During this process, she also accidentally created and gained access to an account using an email address that belongs to someone else with the same name.

She called Amazon support. The first person she talked to just told her to do all the things she had already done. She humored them by repeating the steps. She told the support person it wasn't working. The support person said she couldn't be helped because she wouldn't do the steps. My girlfriend asked to speak to someone else who could help her and the support person hung up on her. She called back and had to talk to two other people before she finally got someone who would help her. (Once she did, it was a process of about 30 seconds to resolve the problem!)

She received some gift cards from a couple of her clients and when she clicked the link, it credited them to the wrong account (the one with the wrong email). She had to call support again and although their solution was ultimately quick and simple it took another 30 minutes of nonsense on the phone to get there.