Relentlessly hounded by Cell C with sales calls every day

Cell C relentlessly hounds me with sales calls every single day, even out of business hours. Clearly, Cell C has no clue how to mine data and how to profile their potential customers properly. If they did know, they would not be wasting their resources attempting to sell their poor quality services to people who demand the best and who refuse to give their business to bottom-of-the-barrel retailers and service providers in whatever industry they may be involved in. Cell C doesn't realise that people profile and assess companies who they themselves choose to do business with, therefore Cell C is stuck on the traditional method of casting their sales net as wide as possible and targeting the wrong market.