Wow, incredible... Something extremely similar happened to me right around the same date. I car was starting to lose power gradually (lights dimming until fading, heaters slowly getting lower, radio sporadically turning off until coming completely off), all signs of a faulty alternator especially considering that the car seemed to be doing a bit better whenever I started it up after shutting it off for a few hours.
Anyways, so I manage to bring my car to the Canadian Tire, talk to one of the mechanics, and offer my opinion on the alternator. He quickly agrees with me, and tells me he will call me the next day. Here I am next morning, getting a call from the CT telling me they changed my battery. Ummm.... are you sure, I ask? Positive. Okay... if you say so.
The next day, since I'm a university student, I was on my way to go home (an 8h drive). About 1h30 in, my car starts having the same symptoms... I get lucky and stall right next to a towing truck, and he tows me to a little garage in the middle of nowhere. I have to sleep there, so hotel, towing gets to around 200$.
The little garage tells me the next morning it was clearly the alternator, and is just stunned that CT didn't detect it. When I get back from my holidays, I go to CT an expect them to at least be responsible for parts of the 200$, but according to them, I don't understand and I'm a bad person, it was my fault, they have top-of-the-line equipment, and the other garage got lucky. The manager was even mocking my situation and really seemed to diss me completely.
I will try and talk with the owner of that particular CT (althought I doubt it will do any good) and will send a formal letter to M. Butts (Head of CT Auto Repair), but it's alsmost not about the money anymore; it's about their total lack of any integrity.