Cartrack made me incur bank charges by debiting an amount already paid, they are refusing to refund

On the 23rd Nov, cartrack sent a WhatsApp message encouraging me to pay the device transfer fee of R880 that I had arranged to pay on my debit order date. Since I had the money I paid and sent a PoP which was acknowledged. on the 2nd Dec Cartrack was sending SMSes advising the same R880 will be debited on my account as per the arrangement I made. I contacted them on WhatsApp requesting that this shouldn't happen as I have paid and that if cartrack debits my account the DO will bounce as I am on a tight budget. I also advised I don't want the DO to bounce since it will attract non-payment bank fees. Cartrack assured me that only my usual DO amount is scheduled, not the R880. on the DO day, the R880 went off, taking money that was budgeted for the normal DO and other things. Following that the normal cartrack DO bounced attracting a R147 bank fee. Car track is refusing to refund the R147 although I did everything to communicate to them to not put me in this situation. Cartrack please pay me back my R147. I sent an email to ***, on the 6th Dec, no response. WhatApp agent said it was sent to the correct department, still no response.