Doesn't want to pay back savings after I cancelled

I cancelled my medical aid with Discovery Health in August 2015 and I asked what was going to happen to the money I had in the savings portion. Discovery informed me that it will only be paid back to me in December 2015. This already made me angry, why do they keep the money for 4 months? I phoned them in November to find out if everything has been arranged for my money to be paid back and was told the money will be deposited into my bank on 14 December. THIS DID NOT HAPPEN! I phoned them on the 15th and was told a cheque will be sent to me. I told them they have my bank details and the money must be deposited into my bank, I am not waiting for a cheque that will probably get lost in the post. They then cancelled the cheque and promised my money will be paid into my bank by the 24th of December. Today is the 5th of January and I still have not received MY!!!!! MONEY!!!!