Such rudeness

I keep getting SMS’s for an account that doesn’t belong to me. Upon phoning to ask them why and to remove my number I spoke to a Sibusisiwe Smith. She rudely told me that I must be sharing my number with a certain Nadia who is the account holder, that I must just delete the SMS’s! What hogwash is that? I asked to speak to her boss but she refused. Please urgently attend to this