I'm only going to say this one more time, perhaps a different way then I'm not going to say another word... tonight.
I have never heard of a country NOT charging departure tax. Whether it's included in your ticket or not is irrelevant. But originally you blamed Belize for having to pay it. You have to pay it no matter what. I was just suggesting that you get with the airline if you're upset that it wasn't included in the price of the ticket.
Speaking of departure taxes (did I read that you are a Brit)? The departure tax out of London is $80 USD if you sit in coach and $170ish USD to sit in first class. Needless to say, I have never been to London. The really cool thing is that EVERYONE pays that out of London - even if you're a citizen!!! What do you think about that, planter61? It's the HIGHEST departure tax that I know of.