Harassment by automated calls

I keep getting automated calls on our company switchboard regarding someone who needs to make a payment arrangement. These calls come in every few minutes. When I called the number and asked them to please stop harassing me, as this is a company and the call could be for any of our 100 employees here,, they just say they can't do that. EVERYONE has a cellphone these days - why do I have to be harassed on behalf of someone else.