Thanks, I tricked it with a cheap blank disc, I managed to get it out no problem.Try and tip the computer on it's side so that the disc drive is facing down while pressing eject, try poking a credit card or something in the slot (but keep hold of one end) and press eject (to try and trick the drive into thinking it's a full-size disc), or apply some double sided tape to said credit card, poke it in the slot, and hopefully it'll stick to the disc and let you slide it out.*
For future reference, slot-loading DVD drives can only handle full-sized discs
*All of these are serious suggestions I've seen on these forums. I've never tried them myself and hold no responsibility if they don't work - but other people seem to have gotten some success from them.