Not sure who's calling 6 or 8 times no msg

Received phone calls and text message. They are looking for someone called Melissa and she had given my phone number. They are looking for her because she owes money and they need to talk to her or legal actions will be taken. I called them back and told the person I don't know how you got this number but I don't know this person they are looking for. They say they are going to notate on the account not to call my number. I get another call from the same company, just a different number, and again they need to talk to me about this Melissa. I called back and told them again quit calling me, I don't know this person and if I get another call or text message I will take legal actions for harassment.  The next day I get another call again this time this is a final notice and if not contacted will take legal actions.  I am going to report this company to the attorney general.