Me and my girlfriend had two Trekker mats which developed bubbles. I emailed Thermarest in UK asking if it's covered and what would be a possible replacement. They confirmed:

"If they are to be replaced Matt, they will be replaced with the trekker mattress."

I just received my replacements and it's Neoair Venture. I got a downgrade from R3.5 to R2.2 and much heavier weight. Without any notification or warning or question if I'm ok with this. After questioning I got the reply:

"We replaced your mattress with one similar in price comparison , specifications and dimensions."

Those models are not fit for camping in UK climate. I have confirmation in writing they sill replace like for like (not to mention their warranty policy). The downgrade was without my concent or options for store credit, other replacements etc. They are now ignoring my messages.

What can I do?