Someone actually called my mum from this number saying I put her down as a reference.  I thought it was for a job I had applied for but it turns out it's a collection agency-

This number is from the University of Colorado Hospital-they call for the purpose of collecting debts owed and they do not consider that some numbers have changed but they still persist in making the calls anyway. Just call them back and tell them that the person is not at your number and that you would like for them to stop calling your number and have a wonderful day.

Dumb heifer! They have no right to bother other people with repeated phone calls for the wrong person.
They had better not call me again or I'll give them some free entertainment.

If it is a collection agency, I guess they deserve to have a phone number too, right! I guess I should pay my bills.

did anyone answer? who is it?