it is unfair, but there is a solution

After a few phone calls on Monday evening, T-Mobile agreed to providing me the unlock code for my mobile phone. The only condition is that the sales person in the store has to sign a paper in which he admits a mistake in the consultation. I was wondering, if someone would ever do so. But surprise, yesterday I got the signature of him under a text saying he did the mistake.
So, my anger and irritatio because of such a way of doing business disappeared. One side not, against the public and especially the media opinion, I think T-Mobile's customer service by phone is the best one I ever experienced.
Thank you guys, at the call center for being patient and problem solving oriented.