Not clear

I bought a house last in a human settlement area. I relocate in July last year. At the beginning of this year January i made payments of plus minus six thousand,they said the money if for property registration. I go this requesting a statement for water and sanitation, they gave me a statement which shows me an amount of R12000 that i owe for water and sanitation, i still don't understand why a huge amount came from. I am much disturbed and very much disappointed.