Received less amount than requested and received sms of full amount but capitec refuse to refund

Am a capitec client and I have made a withdrawal at capitec ATM and received the amount which is less than what I have requested but received the SMS of full amount which I have requested and I thought my money will be refunded like what other big bank does and was not worried because i was not the only person, later I went to the branch to consult about it and they had opened a call for investigation later the call was closed without being notified or refunded. So I think is much better to save the money that I work hard for than to trust this brand