Faulty product

A technician has been sent out to have a look at my fridge 12 June 2019 the feedback received from him was that the fridge needed more gas, which this is the second time that the fridge has been filled with gas due to gas leakage. I am not happy with the service and the product sold to me from Defy and yet I haven’t had the benefit of using the fridge for a full year, it seems to me that I will have to call every 6 months for the fridge to be filled with gas. Also there is a new leak from a grey pipe that is connected from the fridge to the back and the copper pipe is covered in ice and it turns white or color changes back to copper. Since the technician refilled the fridge (12 June 2019) it has been making a funny sound. Job number: ********** . There is one of two options that can take place here either Defy replaces the fridge with a brand new one or give my money back so I may buy a new fridge from a different brand where I would probably find more joy in using.