RCS- is it necessary or viable to harass people? Especially for no good reason?

RCS is a business that handles accounts for retailers. It seems that there modus operandi is to harass people from the moment they open an account ( I opened an Edgars account in late February, and they harass me daily for money that I don't owe, and I have proof that I have paid in full on time.) in order to garner the small change from people generated by their odd system of having call centre staff harassing people endlessly, and then charging the client a fee for eg-sending smses, email.