Need my money back

This month i have paid my moms DSTV as i usually do every month,guess what the next day they disconnected my mom decoder teling me i owe the them extra money .i have 3 decoders that i have connected.which i don't even know about it.i called asked them to reconnect my dstv as im not responsible cause my self i don't even watch dstv.Dstv its a robbing company now they are even refusing to refund me back my money that i have paid as I'm not receiving a service.all i need its my money back and cansel with them will found something better where i can get a better .service.i don't want to be **** paying money for service i didnt receive.