Very poor service

I have a defy gas hob. It needs a new knob for the oven, and 2 gas igniters. A company came out and said he didn't have parts, but would order and come back. That was on the 24/3/21. Today 21/7/21 I am still waiting. I have contacted Defy themselves numerous times, only to be told that they are still out of stock. I think for a company as large as this it is just not acceptable