Just bought a car from dace matt was a great help - highly recommend!

I bought a car from Dace on the 13/10/23 and initially I was satisfied until lately it started to missfire really badly. Just to be clear the car has covered 5000 miles since I purchased it from Dace. On investigation the cause of the multiple missfiring is due to Dace fitting cheap spark plugs to the car, the plugs for the car are a dealer only part and it seems Dace just threw in whatever they could find to fit as long as they were cheap. The correct plugs are £17.85 each before VAT and Dace fitted plugs that were £3.59 They were also 10mm too short and the wrong electrode material and the incorrect heat range. This has lead to the ceramic around the electrode breaking up and dropping into the combustiom chambers damaging the engine on two of the cylinder. You can see from the pictures the ceramic missing around the electrode and the substantial difference in thread length. So far Dace have ignored my complaint about their incompetent mechanical fitters. I mean, how incompetent can they be to remove a set of plugs that were still within service interval and replace them with plugs 10mm shorter? Before buying a car from. Dace, ask yourself would you want their fitters working on what will become YOUR car? Trust me, you really don't....... Factually backed up by pictures and the invoice they provided for the pre sale work carried out. This was provided by the salesman becaise I questioned the oil change they said would be done because the engine oil was black and smelled contaminated with petrol!