Refusal to Refund my Credit

I overpaid my account with Multichoice in January 2018, we then moved house in Mar 2018 and had requested for the services to be disconnected on the 28/03/2018 and a refund of +-R1600 to be credited to us. We were then advised what documents we need to provide, which was done and a reference number was given. The request for refund was done on the 03/04/2018 with a turn around time of 3 working days. Today its the 15/05/2018 over a month later and we are still waiting for our refund. Each time we call we are reffered to a call center agent who assures us that this matter is receiving top priority and the refund will be credited in no time. We have spoken to Busi Maduna, Mpho Malisa, Samkelisiwe Lebeloana and lastly Muhammed Hanif. None of these people that we have mentioned their names managed to finalise this matter. Apparently my refund was credited on the 18/04/2018 to a different bank "City Bank" using our bank account number. I am suspecting that someone has used these funds for their own hence DSTV has failed to refund them back to us. I am foing to escalate this matter further than Hello Peter if I don't get my refund by COB today