Nope. Use Discovercard, I've used them to cancel services for me. All you have to do is say you tried yourself and then they'll close your account, and open a new one. It's not enough for them to change your number, as the old number will still work. Problem is it will cancel every autopay connected to that card, so it's a nuclear option.
No impact. The thing that would lower your score would be if it resets the account lifetime. But every time I've done it, the account lifetime has been the same, and there are no inquiries on my account, so it seems like Discover has a way to do it where it doesn't impact your credit.
