Terrible service no help whatsoever

So, I've been applying for a cancelation of a contract which is by mondo and MTN as it hasn't worked from day one .. I've requested to cancel this since I'm gotten it in june ... every month without fail I am debited by mtn and it is such an inconvenience as I have to go to the bank each month end during its peak during a pandemic with a newborn baby to reverse this transaction.. I've called,emailed,whatsapped and facebookers both Mondo and MTN and nothing has been done. I get the same message that the cancelation takes 48 to 72 hours but how many 48 to 72 hours have I waited if I am cancelling from june .. agent's cant direct me to anyone higher and constantly tell me the same thing that I have to wait for the cancelation .. what do I do going forward as it's the worst inconvenience for me and my family