Did the same thing here. So I gave him the number of another telemarketer that had been calling. Use can use the numbers of bill collectors, too. Really makes my day when I turn them on eachother.
This was most likely a scam. VERY RUDE, demanding, and yelled to talk to the credit manager. I knew something was off when he said the controller's name that worked here years ago.
Got a call from this guy earlier this week. Very nice guy. I had a good laugh with him and ended up doing some business with the fellow. He called pitching his collection services and gave me a great rate of 18% on an account that was almost a year old. Took him two days to collect the account. Very satisfied and was a joy to talk with. Thanks for everything!