Travelstart Not Willing To Assist With Refund

I booked flights with ABSA Rewards Travel on the ABSA Banking app. I then called through in an attempt to stop the booking and get a refund. The refund was actioned but Travelstart went ahead and debited me. All I am being told is that I cannot cancel and I cannot get a refund. ABSA have been no help at all and keep directing me to Travelstart who just keep me on hold all the time. Absolutely horrible experience and will not be using ABSA or Travelstart to book any future holidays.