Unfair Billing

I bought a house in 2010 in Evaton West in Bervely Hills. Since then I haven't received any statement from the municipality for my rates. Suddenly I have received a call from attorneys to inform me that my account has been handed over for collection. My account has a balance of R 37,000 outstanding. I have since 2013 relocated to Johannesburg due to work reasons. I really don't understand why my account is so high as I have for almost two years never entirely utilized the municipal services. I would like to settle my account but I cannot afford to pay for the services I had never received. I do understand that we are being charged a flat rate, but why must I really pay the same rates as a family which lives around the area full time. I have tried to visit the municipal offices but no one seems to help me.