Well, they did help me.
I also had the "fail too many" problem.
I send an E-Mail to whatsapp support and asked to unblock my account.
They answered and unblocked it after on day and everything worked fine afterwards.
I guess it would be wise to not mention the 'N9' or 'Wazapp' in the Mail, though. This should only complicate things because they cannot provide support for Wazapp, I suppose.
I just told them in my E-Mail that i switched my smartphone and got blocked somehow.
You emailed them 7 times? In what timespan?
You should keep in mind that whatsapp has probably a quite small development and support team and I'm sure they get LOTS of Mails right now.
Spamming the support probably won't accelerate things.