I can't see them ever letting you get away without paying for the repairs
and I cant see you being able to prove say under CRA that the fault was there at point of sale and claiming against the retailer.
Legal protections for armed forces personnel and Veterans serving in operations outside the United Kingdom (open consultation)
READ MORE HERE: https://www.gov.uk/government/consultations/legal-protections-for-armed-forces-personnel-and-veterans-serving-in-operations-outside-the-united-kingdom
lets put it this way
if you were still in the UK
and you stopped paying
they'd sell it on to a powerless DCA.
they could eventually take you to court
but if the AC is that old
and the balance is mostly if not all bank charges and the interest they attracted
then most claims we help on are defended upon those lines and most DCA's either give in or lose the claim.
Don't touch them owe me £500 since January 2019 make excuse after excuse. Seem they always have software problems sending money out. Keep saying they will call back or email nothing been chasing it now for 6 mths the phone staff always have the same banter we will chase it up and get back to you then nothing!