I bet Apple didn't give them permission, they never want their logo to be used for marketing purposes for any reason. There are no takeaway Apple-branded gadgets for instance (while I have tons of tshirt/pens/gadgets with logos/products of any technological company in existence), and many shopping malls in which Apple has a store can't show an Apple logo on the big ads panels outside.
When have you ever seen Apple as a reference customer? This was probably some unfortunate Apple employee using their corp email account for the receipt to be sent to. It could have even been a retail employee, which isn't as much as an endorsement as an engineer working on UIKit for example.