Can't get refund and requests are ignored

I've been struggling to get my refund for almost 6 years now. I've sent many follow up emails. They sent me the refund form a few months back which I completed and went to the bank for the official stamp. After returning the form with required documents, I received no more responses after sending so many follow up emails. At one stage I was told to go into the office and I said I'm not in Pretoria anymore. I asked them to explain to me the reason for having to go into the office if I have returned the refund form. I was then ignored again.