Agent giving a run around with returning the deposit

My family and I rented a townhouse through RentalsDotCom in Pietermaritzburg for 4 years and we were never late with payment throughout the 4 years. We put in a notice to vacate the house two months before the vacating date. We were rushed by the agent to move out no later than 31 December 2018 because new tenants had to move in. We comp****. On 31 December 2018 we moved out completely and an exit inspection was done by 12H00 noon. The house was well in order with no damage whatsoever. The agent promised we'd get our deposit back within 2 to 3 weeks, she said we have to wait for the water bill so that they can deduct that amount from the deposit. The water bill was emailed to us a week later but no deposit. We're on the 4th week and still no deposit. I have tried to call the agents but they give me the run around and promise to call me back but they never do. This is the thanks we are getting for honouring our end of the deal.