Unauthorized permission of Cell C

I'm a client of Cell C for the past 10years and is very disappointed in how they adress my query regarding my monthly bill which has increase with approximately R167. 00. I app**** for 2 contract Sim cards which was R149. 00. When I view my bill in the beginning of the month I contacted them requested why my bill increases with above amount. The consultant inform me that they will investigate the matter cause the information on their system showed that I was up to date with my account. Since then they did not resolve my query. During the week I received an sms from them that stating that I subscribed to wacky videos in which I inform them today that I had no knowledge of subscribing for videos on the Sim contract number caused the 20 gig data contract which I received on a monthly basis allow me to watch video as much I want cause my data has never being depleted monthly. Anyway this action of Cell C to automatically subscribe contract clients without them knowing about it need to stop cause it is ***** and ****************