OLD MUTUAL ATM REQUEST R600 to receive R150 and the manager is not willing to compesant

my experience at old mutual nelspruit brown street i went to the ATM using my Sassa card to withdraw R600.00 only to get R150.00 i spoke to the receptionist she said it will be reversed into my account in an hour a day passed i had to go back the next day to the branch.they said i must go to Sassa to report and get a slip but Sassa couldn't help neither.whats happening to the banking systems and ****s?now i lost my R450.00 and the manager says there's nothing they can do please help me is my sons money.there were other 2 more ladies who had the same issue and they complained but because they are using the old mutual card they told them it will be refunded.the staff is not well trained t handle issues when it come to complex matter. it was so easy for them to say they wont assist me with the matter they never even bother to take my information and report to head office.they are horrible and they dont know how to do their job.