I never thought unsubscribing to a newsletter takes up to three working days.

Possible reasons:

• We need to verify if you clicked the unsubscribe button by accident.
• We need to check if someone else unsubscribed on your behalf.
• We need to make sure there is no hiccup or foul play on our email marketing tool
• We need to follow strict procedures similar to that of postal mail opt-outs.