It's really not worth taking the whole fan in for repair. Like others have said, a new remote is super cheap - and the advantage is you can order it directly from Mondial or from online stores without having to go anywhere. The only problem is figuring out the exact model of your fan to make sure it's compatible, but it's normally written on the label on the back or underneath the base.
Just pay attention to one thing: before you buy a new remote, check if it's not a battery contact issue. Sometimes the spring in the battery compartment gets corroded and you think the remote is dead. Open the compartment, clean it well with a dry cloth or a rag with a bit of vinegar, let it dry properly and try again with a fresh battery. If that doesn't fix it, then ordering a new remote is the right solution.