Paintwork gaurantee a joke

We have a bakkie single cab that we bought in 2017. We did our business branding on it, were the sticker kept coming off. When the sign writers try to fix the problem it was brought under our attentiin that the reason why the stickers kept coming lose was the clear paint that peeled off. When we went back to isuzu they just said its not their fault even thow we have a 2 year guaranteed on paint work. This is the second problem with isuzu after our bakkie kept replacing brake pads after 9 000 km, when the first pair lasted 40 000km and now our brake drum is damage. I have been a isuzu client for 14 years now with 3 isuzu bakkies. I will never buy a nother isuzu, im switching to toyota.