ABSA ATM technical error

My mother who receives old age grant went to an ABSA ATM to withdraw her grant and twice the ATM displayed a technical error and printed receipts starting that transactions were unsuccessful and money will be reversed. I then contacted ABSA call centre and they promised that money should be back in her account by close of business yesterday. She tried again this morning and money still not in her bank account. I contacted Post Bank and they stated that ABSA only reversed one transaction hence she can't she money in her account. Please assist urgently this is quite an inconvenience for an elderly person .