It sounds like the drainage channel at the back of the fridge has become blocked.
Condensation is a common occurrence with fridges, there should be a channel at the back of the fridge which collects the water and then takes it to the pump where it is evaporated. Often you find the small hole (about 5mm in size) at the back of the fridge has become blocked.
If this isnt the case, it may be worth checking the door seals, as a poor door seal will increase the amount of condensation exponentially.
If the door seal is making good contact around the fridge, the next step is to arrange an engineer to come out and check the thermostat is regulating the fridge temperature correctly.
Please let me know how you get on, checking the condensation outlet and the door seal.
I havent heard back from you in the last day or sp, and just wanted to check if you still require assistance, I would appreciate it if you could rate the service received.