Vodacom Invalid ********* hand over

My contract ended with Vodacom in 2019 but for some reason Vodacom upgraded my contract for another year or 2 without my knowledge or consent. They apparently have been sending correspondence for arrears amounts and interest accumulated to the wrong email address and telephone no as my company closed last year and everyone was retrenched. There were no letters in the post either. On 01.3.2021 I was informed by a recruitment agency that I was handed over in Dec 2020 but I received no notifications in 2020.No one bothered to call my cell no and inform me on extended contract that I did not agree to or heard of but instead they contacted me to offer fibre. How is this legal??? Why should I pay for arrears on data I did not receive or liable for extended contract of data 2Gb for R109 with probably interest bring charged. I called the debt collectors to give them my personal email address as work email not in use. They never picked this up until I called them 01.3.2021 I'm being charged extra when they have been emailing an invalid email address??? Why did their systems not pick this up. They are not doing their job and keeping me accountable for their inefficiencies. Totally unacceptable. When calling *** and *** answering machine of no use either as says invalid data no and try later. Tried later and still useless.