Having worked in a bank before, I really can say I have seen a lot of people being defrauded with their cards.
Some could have been avoided while some were inevitable because the fraudster already had all the numbers on the Atm Card. Although it could still have been avoided if prompt action was taken immediately.
There was a case of a customer who was a civil servant and had just borrowed a loan from the bank. She got a call from a certain guy who told her he was calling from the bank, asked for her card details and made away with over 500,000 naira from her account a money she had signed to be paying with her salary for the period of 3 years. How painful.
Please note, on no account will the bank call you to ask for your card details if anyone calls you tell them you will come over to the bank to see them in person. Do not fall into the hands of fraudsters.
I have compiled different banks protocols in blocking your card I hope it helps you during an emergency. And if you don't have your phone with you when it occurs please go to the next available branch of your bank tell them it's an emergency and block your card or temporarily freeze your account.
To Block your card Dial *770*911#
To Block your ATM Card
To Block your first bank Card. send “BLOCK” to 30012.
For Sterling bank contact their customer care
Access requires you to just dial this number for ATM card blockage
For Wema to block or deactivate your card send CARD ATM OFF to 33352.
Simply Dial *909#
And follow the instructions
Text BLOCK CARD NUBAN via SMS to 20123.
Type STOP (ATM Account Number) to 08063262265.
Dial *329# and follow the instruction
For Unity And Keystone Bank Call their Customer Care.
Please note that most of the above mentioned codes require you to dial from the number you registered with your account.