I bought a Samsung 660L fridge in 2010 and the warranty was for a period of 5 years, between 2010 and 2015.
Throughout the period of the warranty the fridge consistently had a problem.
The freezer has always worked just fine but the other side is defective, it does not cool.
On several occasions the fridge has been taken for repairs, it would be ok for a few months and present the same problem again.
It is now out of the warranty and has presented the same problem making it unfit to use.
I suspect you might be out of luck.
As you seem to recognize, the warranty has now expired and technically you are therefore not entitled to free support from the supplier of the fridge.
I know this isn’t very comforting but what you should have done is to formally reject the fridge during the warranty period as not being “of merchantable quality” as required by Section 13 (1) (a) of the Consumer Protection Regulations.
What, you might ask, does “merchantable quality” actually mean?
The Regulations define it as “fit for the purposes for which commodities of that kind are usually purchased, as it is reasonable to expect in light of the relevant circumstances”.
A fridge is meant to keep things cold and if it doesn’t then it’s not of merchantable quality.
By coincidence I’ve got almost exactly the same fridge and I even bought it from the same store as you.
Just a matter of weeks after I bought it the fridge side of it went wrong, just like yours did.
We mentioned “merchantable quality” to the store manager and the next day an entirely new replacement fridge was delivered.
Even though your fridge is no longer covered by the warranty I’ve contacted the store manager and asked if you can’t be assisted as a favour to you, given your long-running bad experience.
I’ll contact you directly to tell you how they respond.