ccs credit collection services I suspect fraud Norwood Massachusetts

This company calls me at my work number.  I ask why they are calling me at work and they say it was "the number they were provided"  I ask by who, and she doesn't answer.  She says they are trying to collect money I owe to Farmers Insurance from August.  I never got any call or letter from Farmers.  In fact when we left, they mailed us a refund check.  So I think possibly Farmers has messed up somewhere.  Or maybe because we were in a collision (not our fault) this company somehow found our name, and that we were with Farmers, and they're trying to scam money out of us.