Mtn robs when customer tries to stop marketing

MTN continues to send me marketing sms'. When I opt to STOP as indicated on the SMS, I am ****** of R25 every single time, even when the words FREE are indicated if I reply to stop this marketing via SMS. I am disgusted with their slyness and, after customers pay for airtime, data etc, MTN still feel it within their right to come and ***** from customers. I want the money I have wasted on the STOP SMS' to be reimbursed and that I be removed from any further marketing lists immediately. I find it deplorable that MTN lies and deceives their loyal customers as they do. This behavior and unaccountable attitude from MTN has to stop. Trying to email a complaint on their site, gives you so little space to write the complaint, that you cannot even get your whole complaint in. I suspect that this is discourage customers from complaining. Very disappointing and disgusting.