Exploitative water bill from afhco

Im staying at afhco at unit 333 at newgate. I received my statement last month August 24th 2018 ...in this statement it indicated i had a water bill of R1889 for that month. This is something i totally dispute since my bill for water has on average always amounted to less then R100 per month. I stay alone and seldom get visitors so i cant use such an amount of water per month. I have queried this amount and have requested to speak or meet with the lady of utilities all in vain. I have been to afhco house on three different occasions and on the last which was the 5th of September i was told that i would only be liable for a portion of the amount . this information was also communicated to me via e-mail and i was given a reference no 169034. However on the 17th of September i received a different sms claiming i am responsible for the entire amount of R1889. Now this is not only stressful and confusing but it really is also exploitation. I find it impossible that a single individual who is working from 7-3 , who resides alone can work up a water bill amounting to R1889 in a single month. Im a responsible person who use my water as well as electricity in a responsible manner. No ways can i have a water bill of that amount