Hello Ahmed,
Thanks for writing us about your problem.
As a first answer, the network Credit Mutuel doesn't exist in Switzerland, but we have agreements with Swisscom Mobile Ltd, Sunrise Communications, Salt (Orange Communications).
If my answer doesn't help you, we recommend you to call our Customer Care (0825 360 200) once you are in France.
As our advisors are not English spoken, I invite you to call with someone who can speak/understand French.
Best regards,
Tommy, conseiller Assistance Mobile