Well looks like you might be due some cash
What you need to do is document everything calls, number, times, etc.
Screen shot the number on your caller id or your cell what ever they call.
If they call your cell phone and its not a business line they are violating FCRA.
When they call your home line depending what they say or do they violate FDCPA.
If it were me I would record the calls and try to get them to violate on the phone.
Because the debt is not yours and you are not the person you should send them a letter CMRRR "certified mail return receipt requested " demanding they stop calling.
If you nail them with any FDCPA violations it is 1000.00 per violation but to get that multiple times you have to sue separately on each violation.
Usually when you have them on violations and you send them an ITS letter "intention to sue" they cough up the cash. It is cheaper for them to pay you before you sue as if you get a lawyer they are also liable for lawyer fees as well.
If you plan this out right you could get some cash.