u/1big_bad_wolf

The option for paid expedited shipping should not be available if the part is not guaranteed to arrive by the stated date. Why would I want to pay to expedite my shipment if it is possible I am going to receive the parts late and still have to pay the extra cost? If the shipping channels are a mess then the capability to reflect that time impact accurately in your ordering system either exists or you should refund the expedited costs. Don't let your brand suffer integrity problems from a lack of attention to detail.