Annoying homechoice

I am a manager of a particular company. An ex employee used my cellphone number as reference when opening an account with home Choice. She has since left the company and it's more than 3 years now. Homechoice keeps calling me and asking for her and I have told them a thousand times that I don't know where she is and they must stop calling me. It's more than 3 years now and homechoice is still calling me 10 times in a day. This really frustrates me and I don't know how to make them stop. Homechoice please stop calling me!!!!