Balance after selling property

When selling property, you "must" pay the Municipality an upfront amount for w&e before the process can continue. They gave their "estimate" and I paid it. After the sale, there were still a few thousand Rand on "credit". I personally went to their office and got the correct claim form and submitted everything as asked. The next w&e statement state that the same amount they owe me was used for rates and taxes, balance R0.00 Needless to say no further correspondence were answered by them