Ok, so I just went to the gas station, I hop off the car and the guy already had removed the cap. I was like "what the?!? that's supposed to be locked". So I fuel up and I see what's up. The way I always understood how it works is, that once locked, it's supposed to spin freely so that it can't come off. The thing is, when I lock it now, it spins a little then gets stuck and when you apply some force, it just pops off.

I was wondering if there's anything I can do? It was -10/15 few days ago, I guess the cold must have messed it up somehow. Anyone had a similar issue before ?

I have the same problem. It began before the winter season and I don't know how to fix it. I guess that changing with another one (and add another key to your keychain) would not be a suitable solution.

Anyone can help us to open/repair the mechanism of the cap?