Teka Charged Me ₺4800 for a Simple Repair and Didn't Properly Clean My Oven

I called the technical service due to a smell coming from my Teka built-in oven. They informed me that the heating element and a part called the commutator needed to be replaced, saying the insulation was damaged. They also promised that the oven would be serviced and cleaned to look as good as new. They took my oven and charged me ₺4800. When the oven was returned, they had only replaced the commutator and done basic maintenance on the heating element, yet the price remained the same. Whatever maintenance was supposedly done, everything looked the same, and they even admitted that the surrounding area wasn't cleaned properly. They claimed I must have cleaned it with a knife or cutting tool, but even a sprig of parsley I had left inside was still there. The technical service charged ₺4800 for a part that costs around ₺400 online. I am filing a complaint due to unfair pricing. If you own a Teka product, avoid calling their technical service. Any local repairman could do a better job for less. I am completely dissatisfied with the service provided and the so-called maintenance and repair, and I cannot accept the excessive pricing.