MTN trying to continue milking its customers

i have been walking into MTN stores and when i get there, they would try and call the collections department of which from three stores, i only got through once after hours of waiting for them to answer the phone. i owe mtn RP801.95 and have requested the following 1) i pay R2500 this month and they debit R1000 every month until my debt is closed, obviously thinking in a situation like this intrest would apply 2) i also requested that they stop invoicing me for a contract that does not exist anymore, since i requested they end my contract because the end date was July 2015 and that they stop invoicing me.<br> MTN,s respond is that 1) they will not accept R2500 because they want 75% of the debt which amounts to R7000 and a cople of cents and then the remaining amount afterwards all in two payments 2) they will continue to invoice me R505.00 contract amount until i pay them, therefore refusing to stop my contract. i am not sure if this calls for me to ask my lawyers to take up this matter but what MTN is doing is really not fair since i went to them and requested that i make an arrangement to pay for what i owe them. is this how they CONTINUE TO MILK THEIR CUSTOMERS FOR MORE MONEY