Advised migration now wasp vulnerability

Vodacom phoned me and to advise a migration from my Sart S package to a Talk350 package around 27 Nov. I agreed to this but since I have found myself subscribed to a Wasp service (since 10 Dec) taking R10 a day and I have no idea how I was subscribed, no confirmation sms just missing air time. Since I use most of my airtime in data I didn't immediately notice this. Also since I don't have a service log available I only obtained this info when I queried how R30 went of my airtime on one day. There doesn't seem to be a double confirmation system for such a service and could very well be subscribed automatically since I have no idea how this happened. After requesting to be migrated back (it seems it not so easy to be subscribed if you're on a post paid contract like I was) now to migrate back it will cost me over R900. I feel that since Vodacom requested and advised me to migrate in the first place and since they cannot protect me against such unwanted subscription services, i should be migrated back without the migration fee.