Signature forged, signed up without consent!

Wow so on 28 Feb I mistakenly entertained virgin active promo guys outside the checkers Kosmosdal. Well I tried signing up after I was told I’d pay R160 provided I have a vitality membership. Well I don’t know how vitality works at that point. Following day a guy from vitality calls to try and help me get signed up. So due to the costs I declined. So 2 days ago 07/03/2022 I get an email from Virgin active congratulating me for being Their member. Wow I’m shocked. Even worse they charging me R470 +R100 activation fee. Well worst of all, my signature is forged in the contract, it’s doesn’t even look like mine. I call Virgin active eco park. I raise the matter. They asked me to send a statement and drivers license (to verify signature). Even now I’m still waiting. I’m thinking of opening a case of forgery. Coz I didn’t even sign for that. Can I get advise or assistance.

Thanks