Service but no diagnosis of the vehicle

I took my car in for service of 100km told them that the engine light is ON but it's probably because it's due for a service. After the service the engine light was OFF but a day later the engine light was back ON. I went back to ford and this is what I was told. We do not do diagnosis unless client request so and you will have to pay R780 for us to check why the engine light is ON. My question to Ford 1. What are you then servicing if you are not going to check if all is in order? 2. Do you just clear fault codes without checking the problem? 3. Is it norml to have a new car less than 3 years old to have engine faults? and I just want to add that there level of service received was not satisfactory. Country Ford Kuilsriver. Khaya : ***