Poor service of Suzuki Espresso at 45000km

I took my car for servicing on 26 October 2022. After service I was told that spark plugs were not replaced because they do not have stock for spark plugs, so I will be called probably the following week to come for the fitting of spark plugs. I drive 250 km return trip to servicing my car.

If they do not have simple items such as spark plugs, i wonder how can they be trusted for doing complex repairs.