Well I done all of forest temple, saved all the monkeys so they were on the other side of broken bridge. I then decided to save the game and quit to carry on later. I then went back on to find that I was at the beginning of the dungeon and all my monkeys were still on the other side of the bridge!! Is there any way of me getting the monkeys back over my side to be able to cross? Or do I just have to start from a new game?

I am pretty sure u will never have to restart a game for that reason. try to look into it by just browsing the level

If you progress through the temple again, the monkeys will automatically go where you need them to go. This happened to me as well, when i got to the bridge, they were automatically there. So try going through the temple again.