(Edit: please ignore the following line, I misread. Kept for posterity.)

The title is incorrect. He threatened to sue but didn't actually do it. Which I'm all for.

(/Edit)

I received, just yesterday, a call from a company claiming they could reduce my credit card interest rate to "up to 0%", but it was obviously a scam as he said he worked both for Visa and Mastercard, claiming it was "the same company and they both use the same Reduce Interest Rate department". I unfortunately lost my nerve a little and called him out, after which he became much more familiar, aggressive and even insulting. Don't have anything beyond a phone number and a name (which is probably fake). Wish I could find the nerve to do this myself.