Rule of advertising - don't promise on a date range if you know you can't deliver on time

I ordered a pair of Crocs boot during Cyber week where i was advised that delivery will be 7 - 10 working days. Today is the 11th day. I contacted support to only be told that the couriers haven't delivered it yet (well duh!). Other than apologizing, Sloane and Santa Cruz didn't offer an immediate delivery to fix the siutation. Instead, they advised that this will take a further 3 days before I receive my boots.

I have bought from other online 3rd party sites before and i think they will probably deliver a lot quicker than the suppliers themselves. This is embarrassing!

Rule of advertising - don't promise on a date range if you know you can't deliver on time