Contract still not cancelled after TWO MONTHS

I am extremely and utterly disappointed with RewardsCo ( Mondo) as they keep debiting my account for a sim card that is not active on my side. I can by no means pay for something I am not using.

I cancelled my contract on August 24, 2020, after learning that I initially had signed up for airtime instead of data. I cancelled my contract via email and there was no response as to whether my instruction had been received and actioned. After Mondo has been debiting my account and charging me double, I tried making contact with them and they have been sending me from pillar to psot with no success. I am utterly disappointed with the service that RewardsCo/Mondo has provided me with.