in order to avoid the problems, next time you want to defrost it, the night before put some of those freeze blocks in the freezer. In the morning or whenever you are ready put a couple of the blocks in the bottom of a coolbag or box and put some of the frozen food in the bag, put on the rest of the blocks and then the rest of the food. Put a washing up bowl full of boiling water in the freezer and leave for about 30 minutes. The ice should then be very easy to knock off. Thoroughly dry the inside of the freezer and then close the door and switch it back on again. When the indicator light shows that the freezer has reached the proper temperature simply put the frozen food back into it.
When I do this (I do it about twice a year) the whole job from start to finish takes 2 - 2 1/2 hours so all the food in the cooler bag is safe,
hope this helps!