Cell c bad consumer practices

For around 2 weeks ago. When I wake up to see my phone I see my phone screen on with pop up from cell for a service for R5. Option you get is yes or no. When press cancel same thing happens next day. The pop up turns my screen on and waste alot of my battery, even though my phone is locked. I also get it while using my phone, a pop up comes from cell with same thing. I phoned customer service and say cell c doesn't do pop ups. But is clear it's from them. Also I month ago in November, I got a call if I wanted to continue my contract and I said no I want it canceled and don't want to continue the service with sim card. But today the 19 december. I find out that It's not canceled and I had to waste my time to get it canceled. I already spoke with an cell c agent I didn't want to continue after I done the 24 hours and said it was canceled. Poor service from cell and also this pop up im getting is also a security concern, as it bypasses the lock screen on your phone to turn on the phone screen. Cell c is completely useless, I'll be stopping the debit order, as I already made clear while in advance I didn't want to continue a contract after I'm done with 2 years I agreed. Now it says it be canceled for next month the 19th. I've had a few times cell c has charged me more then double for my contract and cell c should differently be investigated for bad services and other practices