Cancel Contracts

I went to 3 different stores during lockdown to cancel 2 contracts I have with Vodacom...all 3 stores response was ...the only way to cancel a contract thats runing month to month...and any other cellphone contracts you need to email to *** I did in May 2020x 2 ..june 2020 x3 and July 2020 x2...but still I get billed every month ...what the Hell is the problem with you service instead im get harassed by phone calls upgrading the 2 contracts every second day....what is you problem cause Cleary your service is unexceptable after 3 emails have been sent and no response..