If you've inserted your debit or credit card into an ATM machine and it said the transaction was successful but it did not dispense the cash but still took money out of your account then you need to contact your bank right away.
The ATM machine should spit out a receipt and if so take that receipt to the bank and tell them that the ATM machine did not give you your cash.
The bank will then investigate and then look at the cameras on the ATM machine to ensure you're not lying about the ATM machine not giving you your cash.
Then when the investigation is over and they find you to be telling the truth they'll credit your account back the money the ATM machine owed you.
If you deposited money into an ATM machine and it didn't credit it to your account then also contact the bank so they can investigate and have the ATM machine looked over.
They will look through the transactions to find out what went wrong and you'll eventually get your money back.
But you need to contact your bank right away so they can start the investigation and resolve the problem.