Angry about exercise bike

Currently I am really miffed about my sister's exercise bike (I use it that's why). It's far out of warranty by now. One of the belts snapped in it so I thought it would be an easy fix. I bought a replacement for £12.46 and when it arrived (this was before Christmas) went to fix it. I found that you couldn't loop the belt around without taking the plastic casing off, and you couldn't take that off without removing the crank arm. So I got a crank arm remover tool for £19.23. Then I found I didn't have the correct tool to remove the hex bolts so I bought a 15mm socket ratchet for £4.99. Tried to repair it today and I found that they have machined the bolts on so tight that they are impossible to untighten. Now I don't know what to do. A £100 exercise bike down the drain all because I can't get at the belt to replace it.