ABSA Idirect refusing to refund my money deducted ********ly.

I did a quote for a new car insurance with ABSA Idirect, everything was fine, but did not take or activate the cover, asked the agent to place the cover on hold, and agreed that we will call back for activation once we know the car vin number as the car was not yet available at the dealer and was still being ordered for us. to my Suprise without prior warning, ABSA deducted R5456 instead of R959 from my account as I already have another car cover with them. i requested for refund, instead of refunding my full amount they refunded me only 2700 which is shot of 1700 with no explanation, and their agents cannot explain were the other money went. am disgusted and thinking of cancelling even the existing policy I have with them. at that time I have been a client for more than 6 years