Realized yesterday when I preordered Friday I forgot to spend the extra $20 and get the faster charging. Spoke to apple online chat and they said was too late to change order since it’s in preparing to ship. Didn’t want to cancel and re order as shipping dates are farther now. When I receive my MacBook next Friday is it possible to go to apple and exchange the power adapter to the faster one and pay the $20 difference? Apple store 10 mins away from me BTW.