Wrong billing

Some years ago I subdivided my stand. Since then I had to accounts for taxes and services. The one account was for electricity and water etc. ***). The other account ***) was for rates only. On the rates account dated 28/07/2015 all of a sudden water and electricity to the value of R3733.00 was placed on this account ***). I send numerous e-mails to their customer care line with no success or reply. I have now received a final demand for this amount. I do not know where this amount comes from for my two accounts was up to date the month before and I keep it up to date.