Being held Hostage by Vodacom

Due to a bad experince with Vodacom, relating to the data loss fiaso, I decided to not continue my contract with them when it expired. My Contract expired on 17 August 2018. Vodacom received their 20 day notice that I would not renew the contract and why. Now that it has expired, Vodacom refuse to port my number on grounds of terms and conditions that I should not be held to as I do not have a contract with them. I am being held hostage to remain with a service provider, i want nothing to do with