fek that I just stopped my debit order! mother ****ers!
In theory you cannot do that if your contract is still in force, check: "4 Charges" in the "terms and conditions":
http://www.iburst.co.za/default.aspx?link=legal_terms
(Read that whole section and you'll see they've got you by the "short hairs")
iburst "OWNS" you and all the other suckers until your contract expires.