Yes, stock is 5wt, 10wt is way to heavy. If they are unhelpfull you can change the oil very easily yourself. Just remove the forks, unscrew the top caps, unscrew the top caps from the damper rod, remove the spring and pour out the old oil, pump the damper cartridge a few times, re-fill with oil, pump the damper rod to get it full of oil, move the outer tubes up and down a bit to get the air bubles out, set the oil level to about 105mm (might want to get the exact spec from the manual - run it at the low setting for woods) from the top of the outer tube with it fully compressed and put ot back to gether.
good luck