Got two calls a day on my cell phone for weeks; no answer when picked up

Has been calling every day for two week.  They call at least twice a day.  I just do not answer.

They have now moved from 1-716-693-9802 to 1-716-693-9819

This is a collection agency from a payday service.  They give you a superior court case number and when you verify the case number it is not valid.

Calls then hangs up. Leaves no message.