Part of the issue is that the store employee should respect the customer and either give him what he wants or simply say sorry, rather than try to substitute and inferior product.
You were at a disadvantage being there for the first time. It's nice to have someone along who knows the descent route so you can do it in the dark.
I'm wondering where all the time went. You got an early start (8 am). I've started as late as 11 am and still made it back before dark.
I've often imagined what it would be like to bivy up there and decided I never wanted to find out.