Phone calls claiming lawsuit, spam or not? Help!?

Back in September 20 , I received phone calls from two or three numbers saying there was a lawsuit against me and I had to call back immediately . However, to call the numbers do not go through , or is something else entirely. Not only called me , but I called my boss too. He kept calling even though said not to contact me and hung up. Finally , seemed to quit, but then today the same person called again , now claims to be an officer , saying he had to contact me as soon as possible and that if I did not call back then so help me God . The number he called from is not even in the format xxx - xxx - xxxx instead of 4 digits at the end is only 3 ( so it seems xxx - xxx - xxx ) , and the resulting number is constantly busy . How do I get these people to stop calling ? They called my friends house also somehow arrived at that number . The boy does not speak English well at all (sounds of India ) and is starting to drive me crazy . This is correct spam ? MedlinePlus MedlinePlus PS . He said it is suit me for a loan application . I fill out a loan application online some time ago , but not receive any money or anything and unsubscribed from what I thought was everything.