Does our Government Endorse Municipality Abuse

The municipality is finding ways to recover their loses by incorrectly charging the loyal customers who pay their Utility bills on time every month . I have a house which i purchased 4 years ago and have never missed a months invoice .2 months ago they added R 214 000 to my account . They claim that the rates they have being using for my invoices was the old rates and now i must back for 4 years .