For example, I buy a bouncy house as a service, but I don't end up using it. I still have to pay for it, because the contract had me pay upfront.
Here's another. I sign up my kid for computer lessons and pay up front. But he doesn't gain anything out of it.
I think it's "lost my damage deposit", but after a quick Google search, that's something you pay to ensure an item isn't damaged.
So what's the word or saying for my case?