Bad and unprofessional service

I called Vodacom sometime in July 2020 to cancel my contract with them.The consultant apparently did not complete the cancelation and i renewed the contract in August 2020 after getting another offer from Vodacom.Now i am receiving a threatening letter that i am owing and i will be blacklisted and permanently disconnected even though the fault was caused by the Vodacom consultant.I called the collections team to enquire about the period of the outstanding amount to no avail.I am now so ****** angry at this unprofessional service provider as this is the second time this is happening