Harasment mbd calls

The most incomponent, rude, arogent poeple i have ever come across. They have been harasing me for weeks for someone elses account. Every time they call n tell them that they have the wrong person and then they just drop the call while i am eplaining this to them. The next person who calls promises to remove my tel no from the system but shortly they just phone again, and again and again. Cant they just get there facts straight before harasing the wrong person. N block there no but it seems they have many tell no.