Megane 1.5 expression 09 plate

Hi there please could someone help me. I have a 09 plate megane expression 1.5 and I have only had it two months. When starting the car with the stop start button it won't start straight away. You can here the click but this can take me maybe 10 times or more to get it started. It has been on a dionostic machine and found no faults. Does anyone have any ideas.

Regards Tina