Unable to cancel expired contract

my contract expired (31 Dec 2019) and i'm assuming im on a month to month package. i would like to cancel my contract however unable to get through on Vodacom cancellation lines. i contact upgrades and cancellation line ***; low and behold the upgrades line works and i get through to an agent; with cancellations though, the line goes dead. Anyways i've blocked debit orders from Vodacom on my bank account....feel free to contact me if you want your R79 per month