Waiting 3 months for a refund

<p>I was billed in error from 1 Sept to 1 Dec 2016. I phoned and managed to get a refund for Dec, however I am still waiting for the refund for Sept, Oct and Nov. I have phone customer service 3 times. I am promised that it will be fixed within x number of hours, or that I will get a call back. This never happens, and the refund has still not appeared in my account. If DSTV charges interest for late subscriptions, then I should be charging them interest at the same rate for the money they are refusing to refund me.</p>