Billing disaster

On 24 March I decided to pay my DSTV account upfront for the whole year, thinking it will save me in the long run. I phoned the call center before making payment to inform them and to stop it from going off as a debit order. The total I payed was R8494. To my shock on the evening of 1 April another amount of over R9000 went off as a debit order to them, leaving me with no money in my account for my actual debit orders to be payed, as well as a penalty from my bank! I called the center first thing the next morning and was assured that the amount would be payed back to me the same, or very next day. I sat with a negative balance for the ENTIRE Easter weekend, not even able to buy the basics needed. Yesterday I phoned again and was told that nothing reflects on their system as having been done when I phoned on 2 April! I was assured that the matter would be taken seriously and that once he spoke to his supervisor it would be sorted out and that I would receive telephonic feedback before the day is over. I never heard anything, still have NO money 1 week later, while Multichoice has over R17000 from me. I am beyond devastated and feel like cancelling my account with them all together.