Cancelling those Credit Cards

[lenox]

An elderly British lady had her bag snatched this morning and was at the cops making a complaint. She found my phone number somehow and asked if I'd help by dropping by her bank to cancel her credit card. I doubted this would work, but since I was nearby (by chance), I tried it anyway.
'Lissen, this lady wants ta cancel her cards...'. 'No problema', said the interventora, and got straight to it.
Amazing.
I'm thinking of a good practical joke to play on one or two people I know...