Breach of contract

I am at a loss of words with MFC. They deducted my car instalment twice on the 24th of December 2015. I immediately called them and asked why and advised them I want my money back urgently. I had called them numerous times before the debit order was meant to be deducted telling them that they better not deduct my account twice and they do just that. It was only on Monday the 28th that I was told by one of their agents Sharon Mace that my refund was released and will take 3 days to get to me. It is now the 3rd of January 2016 and I have nothing. I had plans with my money and now I am just sitting and waiting for them to respond. I sent another email yesterday and there was no response. I have no idea what to do now. How can they say 3 days and I am still waiting . This is ridiculous!!!!!! I never agreed to the other deduction so why am I being made to wait like this was my fault?!!!!!!