FLY-BY-NIGHT DEBT COLLECTOR

I bought goods for a friend who fell behind with payment last year though she has never stopped paying substantial amounts regularly. Due to the fact that the account went into arrears it was handed over to a debt collector despite the regular payment. This man obviously does not know what on earth he's doing because he harasses me almost on a daily basis. He is absolutely rude! I always answer when he calls me and did explain that payment is being made however he continues to call my cell and work phone. In this week alone he disclosed my personal information to two colleagues who answered the switchboard. Since when is a debt collector allowed to do that? Furthermore, when I called him this morning in response to a very unprofessional and threatening SMS which I received from him, he wouldn't give me a chance to speak (I have a witness) and began shouting at me. As far as I know, if an account is being paid, the retailer cannot repossess any goods. He said that since I couldn't talk to him this morning then he couldn't talk to me. I am horrified that such a huge company can hire a debt collector who seems to have had no training whatsoever and chooses to resort to scare tactics