AIBU to pissed off I was charged for hot water?

[AprilDHarvey]

I've recently started taking my own lunch to university in a bid to save money and in the cafeteria there's a machine that gives out boiling water. I used it today to make one of those mug shots and when I went to leave one of the employees (rude at the best of times) screamed at me it costs 20p for hot water.
I was so taken aback and embarrassed that I didn't question it but is it just me that thinks it's totally outrageous to charge for hot water our of a self-service machine? I know 20p isn't a lot of money.

[HPsauciness]

Our uni canteens aren't just canteens, they are social meeting places, places people go for work meetings, do course-work together, they are deliberately designed not to just be accessible for those paying to eat/drink at that time, but as multipurpose work spaces. As such they provide free water anyway, ours do, so frequently students sit there drinking water or filling bottles and doing their work. Perhaps yours is more of a cafe cafe in which only people eating would be in there, hard to say without knowing the design.

I think for hot water, a small charge of 20p is actually fine, given they do have to heat it and provide the cup/wash it afterwards (not like the cold water dispenser which is free standing and you can use plastic cups or your own bottle).

Apparently only licensed premises have to provide free water, cafes can do so at their discretion- which you have found out!

[WhereYouLeftIt]

"For the record, there was no sign."
In which case I would be insisting that a sign was put up. But I am a bitch when it comes to dealing with people who scream at me.