Bad service dstv.... Demanding more payments.

Bad experience for 2 weeks with DStv requesting more and more money to keep my services connected. Charging me for 2 year contract with no service. They charged me for a 2point installation but take a lot handed me the decoder and left. Got a private Installer, paid R500 and no refund from dstv. Decoder gave up 2 months later, was told they will replace it. Still nothing. Then was told to take it to a agent... 2x.keeps getting a no signal error, dstv was suppose to send a technician nothing yet. Then for 2 weeks now I have been paying my account. Every consultant who contacts me DEMANDS a higher amount until I am told to pay it or they will disconnect. They said I have a credit, but now there is no credit and I must pay the cancellation fee of the contract for the 3rd time. Apparently the supervisor wont assist because I must pay my accounf or fee else.... Even though I have everything in writing.