I have a 2015 CF 800 with 130 miles on it and the brakes have squeaked bad since day 1. Our dealership here could not or would not fix the problem, not sure which. Can someone please give me some ideas on what to do? Is there a way to adjust the rear brake? I am thinking it may be dragging but not sure.

My Z does it when I don't clean it well.  But stops after it's cleaned. Try some brake cleaner or new pads.

I had that problem with my Z Force when it was new.  My solution was to find a big hill, shift to neutral and ride the brakes pretty hard on the way down.  I figure that heating them up good burned all the oil and manufacturing crap off of the pads and rotors.  Never squeaked again.

[2015 Z Force 800 53/Trail EPS]

Without looking at the manual I don't know what brake system the Cs have but if disk like the Zs and Us there is no adjustment. But like bezerk1 says, they usually will stop when broke in. If they got glazed it will take a while. One could get them muddy-wet and slightly ride them a bit to grind some off, or remove then and rub them on some sand paper and rough-up the disks or just try getting then good and hot once like bezerlk1 says. One word of caution though about heat..the disks can warp.

The C-Force have a driveshaft brake in the back and there isn't an adjustment. The entire brake system is 3 calipers/rotors. I haven't had an issue with squeaking, however my brake performance is awful.

On the newer cforce they removed one of the brake handles so you only have a right brake handle and a right foot pedal. I believe the handle and pedal activate all 3 calipers (2 front, 1 rear).

I would try giving CFMoto a call and see if they dealer should fix it, maybe your dealer is being lazy. My dealer has made two warranty repairs to my brakes (stuck calipers) maybe that is what's wrong with yours as well.