If the mirrors work at all, it's probably not a fuse issue. It could be a number of other issues...frayed wiring or loose connections in the power mirror circuit, a bad mirror switch or the mirror motors are bad. It's unlikely that both mirror motors went bad at the same time so I would suggest checking the wiring and connections and the mirror switch for problems.
The mirror switch itself runs about 20-25.00 online or higher at a dealer....check local salvage yards for used ones if need be. You can test for power at the mirror switch... set the switch to either side and see if you are getting power in the wiring that goes to the mirror and test for power to the switch itself with a testlight or voltmeter. Test for a good ground as well. If you are getting power to and from the switch then check for frayed or damaged wiring in the door pillar rubber boot...there is a rubber boot or flexible conduit that goes in between each front door and the door pillars of the body. In some cases over time, the wiring inside that rubber boot for the mirrors and power windows and locks can get frayed and break from opening and closing the doors. You would have to cut a slit in the rubber boot and inspect the wiring inside for fraying/damage. Being an 07 model car, it's not likely that is the problem but it is a possibility in some cases.
Mirror switch at Partsgeek,com...
http://www.partsgeek.com/gbproducts/TC/17833-06015011.html?utm_source=google&utm_medium=ff&utm_content=TC&utm_campaign=PartsGeek+Google+Base&utm_term=2004-2008+Chevrolet+Malibu+Mirror+Switch+Replacement+1240116+Front+Left+04-08+Chevrolet+Mirror+Switch+2007+2006&fp=pp&gbm=a&gclid=CMCi3oi_57sCFQlgMgodVSYAGA
More info on how to test for power....
http://www.justanswer.com/chevy/4y861-chevrolet-malibu-2005-malibu-newer-body-electric.html