NO SIGNAL, NO SERVICE, THREATS AND MONEY HUNTERS

I cancelled my contract in January. I paid everything on the 9th of Feb. Because vodacom rarely has signal these days. I emailed everything through. Random in April I see on the app that I owe R400+ So I EMAIL them. No response. As of last week, I have people phoning me daily that I need to pay. Today I received this threat: Immediate instalment of R250.00 is required on your VODACOM acc.Call us on *** to avoid handover.Ref: I AM NOT PAYING FOR YOUR INCOMPETENCE! I canceled the contract, I paid, YOU need to update your systems! 1 lady even said if I could only pay R100 it would help. Money is not the problem! Vodacom is the problem! They don't have signal in the 1st place! They didn't cancel my account! For what must I pay!