They have been calling my boss at work about me and my cell phone.

If you had a lawsuit against you, you would receive a court summons via process server (or in some cases, certified or registered mail).  You wouldn't receive a vague, threatening phone call.

Are these people serious?  Talking about a law suit of 50,000

Some forgien person said I had legal matter w them! Blocked this number

Called me on my mobile number. I didn't pick up.