Meter reading dispute.

Hi, We have received a pre-termination notice letter from the municipality stating that we owe R18,481.70 where as in January we were charged R3,965.23 which is not right because the money accumulated due to estimated reading. When called the municipality I didn't get help from Vanessa Tsatsi explaining how it got to that amount. The estimated reading on the system is 2528 and the actual reading was 2970, but today when I checked my reading is 2912,467. Please help us in resolving this matter since we didn't get help from the institution.