Mechanical issue

I have taken in my car on tuesday 13 Nov 2018, because my head gasket was mixed with oil (blown). It also came to my dissatisfaction because i had taken then car for a full service at Renault Hatfield. And weeks later such a thing happens. I also have a feeling that that dealer is stalling because i have to personally call them everyday to ask about the status of the car. This is totally unacceptable, i am totally in the dark and for 3 days now. I was only called for authorization so that they can strip the gasket and find the problem and still today they claim to be "looking for the problem"