I used a rust prevention product while renovating a car, but within months the rust started to come through again in blisters. I will now have to start all over again, which will result in additional cost. I have photos taken while using the product. Do I have a claim for my extra costs, and would this be against the manufacturer or the retailer?
If you complain to the shop where you bought the product and show them your photos they may well give you a refund. If you want more you would probably have to sue both the manufacturer and the retailer, which wouldn’t be cost effective since you would need expert witnesses and the outcome would be uncertain. You could approach Trading Standards via the Citizen’s Advice Bureau if you feel the product’s claims are misleading.