misleading offer

I cancelled a contract with vodacom and while on the phone offered me a R65 airtime and 500mb data for R39.on 1/9/2020 I checked when this offer will start and found out this was a contract worth R203.99 a month.I was hours on the phone trying to cancel but they refused.four people I spoke to was bonisiwe,Inam.tume and mfundo. I stopped payment but they phone several times a day.