Really no offense here, and I do see the frustration but it was your fault. Any host that has a software made for billing, well its not their job to check your email and make sure its up to date. Its your responsibility. If they sent the email out originally ask for a copy of it, its not that hard to pull logs, right?
Also, on a personal note (because honestly things like this I just can not stay out of), if you have two accounts, point them both to the same reliable email, not specifically one that is for the domain you have an account for. When you leave yourself in a place that could end up being a hole, you have no one to blame but yourself.
Support - awesome reply, I just do not agree with it.