The trouble is, a warranty is a commitment to repair or replace defective parts only within a specified time frame. When does the warranty run out on your machine?
I'm no expert but I would take this up with the shop or retailer. You bought a 'high end' appliance costing more than average in good faith it would last.
The key phrase for you to quote to them is ‘Merchantable Quality’.
Maybe this model has an ‘inherent fault’, that is an error in design. If this design error was present at the time of sale, (even if you didn’t immediately notice it), it means that the product was not of satisfactory standard, and so would not be considered to be of ‘merchantable quality’ under the Sale of Goods Acts and Regulations.
Goods are considered to be of ‘satisfactory’ ie 'merchantable' quality if they reach a standard that a reasonable person would regard as satisfactory, given things such as description and price.
Durability is one of those things that you, a ‘reasonable person’ should be able to expect, and how much durablity would depend upon what you had bought.
I know two years post-purchase is quite a long time ago but assuming there's no heavy handed treatment, I don't think a reasonable person would expect a washing machine door to keep failing! Have you checked online to see if the particular model you have is prone to this happening?