Why isn't my app working?

So I brought Cut The Rope a couple days ago, and it was working perfectly fine on my iPad (its na iPod touch game). This game cost me $1.19 I believe. Anyway, one or two days after I bought it, the game stopped working. I have no idea why. When I press on it, white writing comes up that says Chillingo in red writing (which I believe is the creator or sponsor of the game), but rather than taking me straight to the game in just exits after 1 second. I paid for this app and it doesn't even work. I'm not usually allowed to pay for apps but I ured my parent that it will be money well spent. When I tell them it dosnt work they are goi to be furious. So guys, do you know how to fix this? Why it's doing this? Any help will be greatly appreciated. Sorry for any grammatical or spelling errors, I'm only 14 and I just learnt how to speak English this year. Thankyou for any help you can provide.