I Can't Open This Stubborn Jam Bottle

I bought this jam a couple of weeks ago and till today I can't open the damn bottle.

I've tried all sorts of methods - putting a rubber sheet around the cover for a good grip, waiting until the bottle is in room temperature, heating up the cover on the stove, etc.

I even brought the bottle back to my mum's place to see if she know of any special tips in opening stupid, stubborn jam bottles. Unfortunately her attempts were also futile.

I think I need to bring the bottle to the office and get one of my male colleagues to open it. I need a pair of strong hands as mine ain't strong enough to open this stubborn bottle.

Note to self: Never ever buy Steffi jam again !!!