This may be a new one. Our dealer filled our car with gas after our last visit several months ago as a token of good faith after some service goofs.
Since our R56 is a fair weather only car we only have had it on the road a few times in the last couple of weeks. Yesterday we needed to get gas as we were down to 80 miles distance left. The gas cap will NOT come off under any circumstance ! Even broke off the plastic portion with a last ditch brute force attempt. Anyone else see this problem. Lucky we weren't far from home.
Back to service this week.

 

^^Geez that sucks to hear.No it hasn't happened to me but I went to fill up for the first time yesterday since getting my MCS and the gas cap is not exactly easy to remove or even put back in.

Explain to the dealership what happened after their good faith on filling it up and have it replaced under warranty or at the dealerships expense.

 

As everything in the Mini... The gas cap doesn't operate like a normal gas cap. It only takes like 1/4 of a turn to unscrew it off and put back on. Maybe all you had to do was pull on it after you turned it 1/4 of a turn... I know the first time I refueled I had trouble getting the cap off and then realized it was already uscrewed, I just had to pull on it to get off...

 

It might be a defective cap. The gas cap should come on and off with ease and not as how you described. There was another member here, if you can find the thread, who a few months ago ran into the same problem you seem to have had where they couldn't for the life of them unscrew the cap off at all. They eventually had to have it replaced and, I believe, they said it was a defective cap.

 

1/4 turn counterclockwise and PULL. It is a very simple mechanism.

 

Hello,
This baby does not move at all ! I'm a machinist so the i've got the concept down pretty good. The dealer wrenched it on ,so Saturday they can get it off. Luckily there is enough gas to get us to the dealer. I tried again yesterday with no luck.

Thanks, Brian