A salon stylist would doubtless know some things about resolving matting, though they're in the business of cutting, so they might suggest that first. I've always had easily tangled hair and long since learned a technique with just my fingers. It takes a very long time, but can work. You start at the bottom ends and and just wave your individual fingers within the hair. It's easier if you aim your fingers up toward your head a bit as you do it, too. You have to work from the very bottom or you'll tighten the tangles. Using both hands I have even gotten thick tangled long wigs untangled this way.
I have had some luck working a bit of coconut oil or the like into tangled hair to loosen it, but you don't want much-- just a couple of drops here and there, perhaps. You don't want to wet the hair with water, though.