Triple billing from MTN

I took out a contract for a laptop with MTN in September 2020. The laptop comes with a Wifi router and two sim cards that contain data. Every month I receive a statement on the 25th of the month, containing my invoice and statement for the months billing and then on the 15th of each month I get billed an amount of R398. I also receive an email 4 or 5 days before the 15th reminding me of my debit order payment on the 15th. This month, June I did not receive any email reminding me of the debit order, nor did I receive an email containing my invoice and statement for my spending fir the month if May 2021. To my surprise this morning I noticed that MTN billed me 3 times more this month, a total of R1456 was debited on my account, instead of usual R398. Upon calling them and having to deal with two rude service consultants, I am told that I requested for a data limit increase hence my bill for this month is this high. I however do not recall requesting for an increase in my data spending nor, did I consent to this. Had MTN sent me an email notifying if the amount to be debited on the 15th of June, like they normally do each month, I would have queried this amount even before the debit order went off, because they are ******* and ******, they didnt send me a reminder of my debit order, because then I would be aware of the incorrect amount that they will debit. So I have requested for them to credit me the extra amount that they debited on my bank account. They promised to send me a SMS confirming my query immediately after our telephone call, but it has been hours now. I have not received any sms from them informing me that they will escalate the matter. MTN I want my money back, that you took ********** from my bank account!!!!!