Vodacom treated me very bad

The company I worked for had a contract with Vodacom. I got retrenched in July 2018 and the company instructed that I take over the contract on a personal capacity as I wanted to retain the number(it was my number ported to contract). The transfer of contract from Business to Individual was done on 02 August 2018(meaning that my usage as individual was suppose to be as from August), but to my surprise, the charges for July 2018(the usage was for the company as the contract was under company until end of July 2018) were billed to me(appeared in August statement). I went to dispute the charges as they were incorrectly charged to individual instead of company, I was told that when they billed the contract was already changed to individual hence I was billed, my argument was that it was never explained that I will inherit the cost for the company for July usage.

I was told that I must go and claim the money from the company I worked for as Vodacon will not reverse the incorrect charges and charges to the company, and another option was for me to pay those charges, I was retrenched and battling, and as a result that amount is still due and now Vodacom has suspended my line, I've used the number in almost everything, banks, cv and everywhere as it is my primary number.