National Debt Advisors - bad service

Good service for 5 years... now nothing Now that I am supposed to have my last payment, it came to light that I actually have overpaid the last two creditors as they have closed their files some months ago. Now I am being ignored as to how and when they will refund me. The Payment Administrator, Mr Baxolele Deliwe working on my account seems to have vanished into thin air. Emails are all ignored. Try and log a query.... impossible, as they revert back "our support Rep has indicated that your ticket has been resolved". What support Rep is that? No emails, no calls.... nothing. Calling is impossible