Mercedes-Benz Cannot Solve My A 180 D's Engine Fault...

My 2020 model Mercedes A 180 D vehicle constantly gives engine failure due to the spark plug. Even though I went to the service for the same error 4 times in total, it was reported that the spark plug was replaced and the problem was gone. Even though 10 days have passed since the last change, my vehicle had an engine failure for the 5th time. Although I requested the service to conduct a more detailed investigation and take action to prevent any malfunctions in the future, I received a negative response. I am having an experience that is not befitting of a Mercedes brand vehicle. I request that the problem be fixed permanently and, if necessary, a more comprehensive change be made.