Tenant withholding rent for Fridge

[Johnny Mey]

Location: California. 

A tenant is withholding rent because the fridge is occasionally leaking on the inside. 

It has been leaking on the inside for about a month now, but I already had professionals head there and told her to contact our maintenance manager to fix it, however she hasn't done it.

Now she is withholding rent. As far as I know a fridge is considered an amenity and is not considered part of the habitability laws. Who is in the right and what should be done?