Rates adjustments from 2011 and 2012

I bought a house from RBA and my bond was registered in December 2013 and I moved in on the 1 June 2015.I went to city of Tshwane to apply for water and lights and I was given a statement with rates adjustments from 2011 and 2012. I asked why do I have to pay rates from that time and they said the rates are for the land that was not utilised during that period. I asked Rba to pay from 2011 to 2012 and I will start paying from the time when my bond was registered. RBA must take accountability and pay the rates from the time when the land was vacant. I didn't buy a land, I bought a house.Their services is so unprofessional and they are busy passing the bug. Their customer services is very pathetic, all they want is people's money and nothing else. Once the house is bought they don't care about their client's needs and complains.I have been following up with Clive and Rahaba from head office in Pretoria and nothing has been done.They didn't even contact City of Tshwane or made proper investigation on this matter.I am sick and tired of RBA and their *******.