Cell C in contravention of CPA?

I don't know what is more frustrating, the constant spam and harassment from your call center, or the fact that I can never use my phone. I receive numerous SMSes from Cell C, with no option to opt out and I am constantly phoned to upgrade or take out new contracts even though I have requested EVERY SINGLE TIME to be removed from the database. I'm pretty sure this is in contravention of the CPA? My main issue however is the fact that I have NO signal, EVER. I cannot use my phone unless I am on WiFi (not supp**** by Cell C). I have just tried to book an Uber, after 15 mins of waiting for signal I gave up. I tried to phone my extremely sick grandfather back after seeing he had tried to call me but it wouldn't connect, and I cannot get through. I get told by your company that now you have roaming with MTN and it's so much better. No it's not, someone is lying to someone and I am sick of being on the receiving end. I have a contract with Cell C, my contract is a payment from me in exchange for services from Cell C, I am not receiving these services and therefore you are in contravention of the terms of this contract.