Standard Bank - Can't Trace Funds or Account

My 79 year old mother has gone several times to various branches of Standard Bank to try find an account she had which became inactive. The staff are totally unwilling or unable to assist her in tracking down her account. As a pensioner I feel this is disgusting and totally unacceptable. I wonder what happens to the funds in these accounts that become inactive and who has benefited!

My Aunt passed away in 2009 and they were advised to close the accounts etc. I am still being contacted by them on a regular basis to tell me of the "new platforms" etc. They seem to prefer helping the deceased rather than the living!