Webafrica won't release line on month to month service

Hi, I took a vuma reach package with webafrica and was dissatisfied with they service, so at my last billing I never pay them, as this is a month to month service I don't owe them anything for not renewing my service, I want to deal with another company, so I got in contact with they agent and asked them if my line will be released due to not paying mind you that this is a month to month service you only pay for what you use, agent then confirmed to be that because I did pay them at then end of the month that my line will auto cancel and eventually released as I wanted, I have proof of the agents statement, so the next day I go back to webafrica chat and ask them how long this will take, they then tell me that's not how it works that I have to pay them whenever I can and renew the service then do a cancelation, I explained to them that yout agent clearly told me my line will be auto canceled because of non payment after some time, now the only time I can make pay ment is end of January and thereafter I have to still deal with them whole Feb then only get cancelation, I don't understand it's not a contract so why is that they can't release my line, all I want is my line released so I can move on to a better service every time I contact web africa they got some excuse and some lie, and try to cover up what they state in black and white, please can you assist with my line release I'm not on any contract with them, I should be able to have my line released as I already have many email saying my service is suspended, so I don't see the need for them to hold my line, I don't want to deal with them, they do not have any proper customer service skills always avoiding what you ask, I'm on vuma reach, my service is month to month its prepaid I pay for the month I use if I did not pay them my service is canceled and my line should be released, please I'm asking you as vumatel provide me with my line release.