Unfair payment

In March I received a message for a discount on my package I took it cause who would take it so last week I get a sms saying that I must pay more than what I pay every month I phone in they say I must pay for March discount cause it was I mistake I don't think it's fair that I must pay for something that I didn't ask for I called more than a R60 airtime and no one can help me they said they will call me back up till today no one called back they disconnected my service now I must pay even more to reconnect this is not right u pay to watch the same stuff over and over again only reason I have dstv is for the kids.