Nedbank is a risky bank

I mistakenly paid R1200 to an incorrect cellphone number using the Nedbank money app. After numberous calls to the call center requesting assisatnce to block the payment made and mark the OTP token received buy the unknown number invalid all i get is a run around. Banking with nedbank is becoming risky if we can not reverse any payment mistakes like other banks. im considering moving to a bank that takes it's clients serious