I find MEC floor staff to be hit and miss. Some are friendly and helpful (whether knowledgeable or not); others are the typical snotty kids type: unhelpful, condescending, obnoxious, (regardless of age)!
But the MEC return desk staff has never been anything but excellent, the few times I've returned things.
By far the time that impressed me most, was when I had bought some trek poles at Monods. The next day, on a mild scramble, one pole completely bent on the last segment. I had NOT been doing anything unusual, and I was a very disappointed.(this was in fact the first pole I've ever bent). When I arrived in Calgary a few days later, I called Monod's and inquired whether they could help me. I did not demand anything, I simply asked if there was a policy that could help me, or at the least, if I could buy a replacement bottom segment from them. The manager came on the line and told me no. Talk to Black Diamond. Nothing at all we can do. "Some people do stupid things. Like prop the poles in car doors, or try to put all their weight solely on one pole while doing something awkward." I laughed at the car door mention, but then she said "we don't know what you've been doing with them". (not in a very jovial manner) I don't mind if the store won't replace them, but this phrase(along with the anecdotes) annoyed me slightly, since their was the implication that *I* must have been doing something strange. I assured her, I knew what the general expectations of poles are, and I had not been using them in an unusual manner. But I was not going to get upset by this, so I simply asked if they might replace this last segment with one from another pole; I would pay for the part, and they could get the part from BD? (particularly helpful, since I don't live in Calgary or Banff, and so there was really no way I could get parts from BD until well after this trip, and I hoped to be using them over the next few weeks) Nope. OK, thanks.
A few days later, while at the MEC Calgary, I stopped by the desk there, explained the situation (to a guy I remember as fairly tall with glasses and curly hair), and asked if by some chance they had carried the same pole(I knew it wasn't in their current catalog), or might be able to get parts. "No, we don't carry that model...but hmm...maybe one of the segments from one our BD models will fit....do you have it with you?"
I went out to my car, got the pole, and off he merrily went. 15 min. later he emerged, announced that the BD parts hadn't fit, but that a segment from another old pole they had lying around had worked! We laughingly noted that the colors even matched roughly, and oddly enough, the way he had fitted it together, it is now both a snap lock AND a screw lock! Price: no charge.
Again, I hadn't even purchased it from them. Fantastic.