Maybe you need to close the account first to prevent the accumulation of the charges related to credit shield. Then obtain documentary evidence that you opted not to be covered by this credit shield and demand reversal of the charges. There could have been some human error involved since the default entries should have been edited or changed to reflect in the system your request to opt-out. Was the advertisement silent about when you must inform the bank that you are opting not to be covered anymore? if that is the case, then the bank is at fault and therefore should revere the charges.

This is somehow related to insurance, not banking. The bank make arrangements with an insurance company who will then issue a policy for a certain premium. Sometimes the bank and the insurance company are sister companies. Now the problem lies where the premium was already remitted to the insurance company and this will cause delay in reversing the charges. It is bulk remitted and again add to the delay. So its really better to close the account.