Rejection of contract hire vehicle rights?

[Crazy4557]

I have a 5 week old Mercedes EQC that has been back twice for a low coolant level warning, both times I've had to drive to the dealer and collect a courtesy car and drive back in the afternoon to collect my car. Second occurrence was just a week ago, I was told by the dealer not to drive it but call the RAC by pressing the SOS button, turned out thats for Fire/Police/Ambulance only so, I felt a right tt. The RAC topped up the water and said it was OK and it went back to the MB dealer to be fixed for the second time. The low coolant light re appeared this morning. They've had 2 attempts to fix it.
What are my rights regarding rejection and replacement/cancellation of contract as I no longer have any confidence in this car?

Thanks in advance.

[Djtemeka]

Let them fix what should be a simple issue.