People did that at my work for over a year and they knew the whole time it was a fundraiser and no one ever owned up to it or payed. That was a shitty workplace.

I'm just confused as to how you thought they were free. At my gym, any food, drink, or fitness products are for sale (at a ridiculously high price). I'm assuming you go to a small gym, so wouldn't these bars be at the front desk with someone working there or at least have a donation box right beside them? We're they labeled in any way? If it's a small gym like in an apartment complex, and there's no sign or donation box, and no one working near the bars, I can't see how it's your fault, but if you ignored those things ydi.

I think whether or not your deserve this has to do with whether or not your gym gives out freebies a lot. I mean you didn't ask. Even if something says free I'm always suspicious there is a catch.

Fork over 14 bucks and problem solved

Take in 14 dollars/pounds next time you go to the gym, 1 for each day you have taken one :)

The gym probably put the protein bars on your bill

The point now is for you to own up to your mistake and pay for the bars, and maybe add a little extra...

Don't you think there would have been a sign saying free? I'm surprised there wasn't one for the fundraiser. You better do the right thing and put in the amount of money you owe.

Very easy remedy for that: throw a $20. Spot down to cover the costs and kind of redeem yourself

Either pay them now, or get the name of the organization so you can pay for them later with maybe a bit extra thrown in when you have the time/ and apologize for the misunderstanding either way. Also, inform the staff that it's not very apparent that the bars are there as a fundraiser - chances are if you've made that mistake, at least one other person has as well.