Purchased a built in oven in January 2023 with a 5 year warranty. The oven itself has had issues with hot spots meaning have to move some items around to avoid burning. Told this is a common problem with ovens!! However, the present issue is with trying to replace 2 knobs that have faded making it difficult to know what temperature and function has been selected. I phoned the number in the info book supplied with the oven. After waiting 13 minutes to speak to someone informed that I needed another number. Rang new number and having spoken to 3 more people finally got an agreement to get the required parts. This took another 39 minutes. To buy the new knobs would cost £52 each. The oven when new cost £400. Why do 2 small parts cost 25% of the purchase price?