Even the OP made it clear that the reason for account closure was not the complaints, it was the violation of the t&c (which now seems clear). The volume of complaints was simply mentioned as a reason not to retain OP as a customer (or at least an HH member).
That seems fair. If OP had been a 20-year member with a large spend and engaged in some minor transgression, perhaps HH lets that go. But, not OP.