I never signed up for this

My number switched off for a good 3 days then i bought a new sim card to do a swim swap and Vodacom told me they can not help as my number is with Blue Label Connect. I don't how this company signs people on their contract without them knowing. I've been trying to get them to cancel me on their contract but they are not helping. Ever since they put my number on their contract my number is not working like before, it can be off for hours in a day and would be unreachable, and I'm losing business because of this company.