Monies due being withheld for 2 years

Joburg City owes me R9000.00 since July 2018. I sold my house and had to take a bridging loan to cover the outstanding balance on elect/water/pukiup. I did informed them that the amount was incorrect but they insisted that I pay first and then sort out the problem. Well it is now almost 2 years down the line and I have yet to receive my credit owing to me. I cannot tell you how many emails and phone calls has gone into this exercise. I not only demanded the money several times I am now forced to get legal advice. Why has it taken them 2 years to refund me this money, surely this must be paid back to the customer without having to beg for money that is rightfully yours. I would also like to mention that I sincerely hope they will pay me interest for the 2 years they been holding my money in their bank account. I am sick and tired of this bad service this to me borders on ***** I know they have had problems with their systems, but with all due respect that is really not my problem, they are quick to take you money but take 2 years to repay you, that is just unacceptable, dishonest and disgusting. A very unhappy customer Mrs M E Castelyn