Nuisance calls from Home Choice Winberg & Independent Newspapers

I have been receiving phone calls daily from this Store, I have never visited it, do not know the lady they keep asking for ...for reasons of security, I am just giving first five digits of her name..Ntom...and my phone number ending 4203. There are ladies calling from morning till afternoon asking to speak to this lady. I am told she bought duvet covers there. I do not know how they got hold of my phone number...I have the same problem with Independent Newspapers...they keep on calling trying to sell us newspapers. It is so frustrating, they call on our landline and I cannot block them. These are all different people trying to make a sale. It is unfair to harass us in this way. I am at my wits end how to get my number deleted from their system. Should I report to the police, talk to telkom, which may not help as these are ladies who are calling from their personal lines hoping to sell something. Should I ask Telkom to change my number? Please help....would be grateful if I could get rid of these nuisance calls.