You can ask again for it to be looked at repaired
even if it is out of warranty
fixed twice during warranty period (for free i hope )

if point of sale will not refund or repair or replace fridge freezer

you will need lots of paper work receipts of repairs and calls and conversations made etc etc
then you have to take the company /manufacturer of the bush fridge freezer to small claims court and try to get money back
parts list
http://www.espares.co.uk/browse/at1084ma732/fridges-and-freezers/bush