Bad & uninformed customer service

My cell phone contract was up for an upgrade. They contacted me and I renewed my contract 5 months ago selecting a new dual sim phone. All good and I received the phone with a new sim card within a week. Unfortunately when I received the phone the drawer in the dual sim card slot was missing. I phoned them the next day and they had no idea what I was on about and told me to send the phone back. In the interim I had set up the whole phone with contacts, emails etc. So I asked them to just send me the new drawer that fits in the slot. Nearly 3 weeks of trying to sort this out and over 8 calls to Cell C, and even going to a Cell C shop, I eventually managed to get a drawer from a friend. For some reason, I couldn't get my data to work on my phone and my old sim was not registered on the network. Eventually, after trying to fix this problem myself I phoned Cell C to see what the problem is. Turns out that the old number is not valid anymore as it was replaced by the new sim card but they did not activate the new sim card. So.... I have been paying for Data and airtime for 5 months for nothing. The worst of it all, is that nobody informs you of this and now I am told to purchase another sim card and ricca it and then phone them again to activate it onto this number. REALLYYYYYY!!!!! Why send me another sim and not activate it one time as it is an upgrade and renewal of the contract...... As far as I'm concerned, this is breach of service as they did not do the job properly on their side in the first place!!!!!!!