Pre paid number converted to a contract without my consent

I have a problem with Vodafone, apparently my cellphone number has always been a pre paid since 2004 and I was shocked to find out that some foreign company converted my pre paid vodacom number to a contract without me knowing, no one has contacted me with regards to this. I called vodacom last month because I had a problem with regards to the WhatsApp bundles that I could not utilise, when I phoned vodacom they said they cannot help me I must phone this foreign company , I was so disappointed with vodacom because I personally think that immediately when a pre paid number is converted to a contract they should notify the client one way or another. I called this foreign company and the agent that I spoke to first was Sindy who refused to give me her full names and surname, only gave me her name is a ref number, she said that they are choosing random cellphone numbers and convert them to contract numbers, my problem is that I am currently unemployed and my vodacom number was linked to my banking app of which I had to go a de activate my banking app. The agent by the name of Sindy told assured me that it will be converted back to a pre paid, I called vodacom the agent that assisted me said that it was converted back to a pre paid, waited 48 hours, phone vodacom again they told me that it was converted back to a contract. I am not running around in circles, I need my number to be converted back to pre paid, the other vodacom agent said that I must go to the nearest vodacom branch to rica my number but when I bought a new phone because l have lost the old one the SIM card was registered and brought necessary documentation to rica it. I seriously need help because Dumsani from the workshop branch advised me to write to hello Peter. My question is how can this foreign company convert my pre paid number to a contract without consulting me and vodacom is not helping me at all but I am using their network. I want to retain this number since all my contacts have this number for personal and business purposes.