how to mend the fridge on my fridgemaster fridge/freezer ?

when the water runs down the back of fridge then into the little hole at the back of my fridgemaster fridgefreezer it just freezes up before it gos into the back i just get a lump of ice to the left and right of the run into the hole,
its not blocked up and its not on high.....iv put the temp number on 1 now, but it still makes a smaller ball of ice and i get a pool of water on the bottom of fridge were the two plastic containers go, its only 3years old theres no probs with the freezer part....please help...with it being on number one its to low. thank you