Stranger keeps you safer than your bank.
Found someone's card in the street and thought I would phone it in to cancel it before disposing of.

Phone lines closed before 5pm.
Tried number on the card and found online.

Used online chat and explained the situation.
No response. 
Tried again. Waited, eventually told to destroy the card. They take no action. 

Summary,
Please use a bank that wants to protect you.