Cell C customer service is the worst I've ever experienced in my life.

I've ordered a phone, 3 days ago it was supposed to be delivered, its still not delivered to this date, I've tried by all means to communicate with them with no use, they just say it's with courier it will be delivered, I can't track it, I don't know their delivery number, their customer service still not telling me what's going on or where my phone is.