Inefficient vodacom

Paid up 3 mobile contracts with vodacom before I left SA to work abroad(have the invoices) Called the *** number to ensure funds reflecting and change to pay as you go effected. 2 have been cancelled but Vodacom have now debited account after 8 months. Sent someone into store, told it probably was not cancelled by phoning it through. How is it possible that they cancel 2 and not the third one. Fed up with inefficiency.