Kia Ceed clutch / who is responsible?

Hello, I bought a used Ceed from a car dealer in December 2023, he currently bought 80k and with 67k. I noticed 2-3 months ago that in the D1 walk, he jerks when starting up. Was then about 3 weeks ago at the dealer, because he has a year warranty and presented the problem. He recognized the problem, however, pushed it either on a resett of the learned coupling, which he can not do, or that the coupling is “defect”, I sol But let me turn to a Kia contract workshop, because this is a guarantee case and because of the checkbook, the factory guarantee exists. Now I called the workshop, however, he told me that this is definitely not a guarantee case, if the clutch is worn out. Whether this is defective, one would have to check, but costs 120-130€, which I am not really willing to pay, already alone, because I have a year dealer guarantee and after a 3/4 year that happens suddenly. the problem, which seems to be a short circuit somewhere, because the boot lighting does not work, since the buy is not, the rear camera is leaking and the picture is extremely pixelated and the Car Play USB slot, also has a wackler, all that, I should inform the contract workshop, which fix it on guarantee. For me, the dealer here takes off the responsibility, but I simply don’t know how to do that. Now I don’t know how to proceed here, because the whole problem is that the car is not a problem. It would be great if I could get recommendations and information about what I should/can do now.