The version of "Cthulhu: Dark Ages" I'm familiar with doesn't use levels, and I'd be surprised if the new version is much different in that respect.
"D20 Call of Cthulhu" does use levels, and could probably be converted to "Cthulhu Dark Ages" easily enough with a little home-brew work and some 3rd Edition D&D reference books. However, D20 CoC, and especially a home-brew D20 Cthulhu: Dark Ages, are weird enough that I'd have to think that the RPG group would have surely mentioned that's what they were doing.
The "Pathfinder" variety of D20 D&D could in some ways be considered a sort of "Cthulhu: Dark Ages", in that it's a D&D variant with Lovecraft references heavily built into the setting, though it's far more a D&D standard-issue-sword-and-sorcery-fantasy setting than it is a Dark Ages setting by default, and would probably require some extensive home-brewing to be properly called "Cthulhu: Dark Ages", and I don't think most "Pathfinder" groups would call their game "Cthulhu: Dark Ages" in any event.
I would definitely get some clarification from the GM and the group about what's really going on with the rules set. I'm suspecting either some sort of home-brew thing that you've somehow been left out of, or there's some sort of bizarre misunderstanding going on.
When you get the clarification, I would be very interested in hearing more about exactly what this group is using for its rules set, just to satisfy my own curiosity. Do let us know what's going on!
Edited by yronimoswhateley, 24 October 2016 - 07:56 PM.