Very Irate Mtn customer

Hi I desperately need help . I have been trying to get in contact with mtn south Africa as I was doubled debited this month without my permission , I can't even go to the bank to reverse that debit ,.I would appreciate it if I can get a response soon...mtn needs to realize that during this lockdown period a lot of us are stressed out and this just added to our stress levels ..I urgently need a refund from mtn south Africa