They are only legally allowed to call you between the hours of 8 am and 9 pm your time. I have given you everything you need to know to stop them in their tracks on page 1 of this thread. You can read it and learn or put up with the harassment. Your choice.
I get calls all the time and never leave a message. Every time I google it the same thing comes up. I don't even have any debt or bills I pay always in full or I do with out.