If they work in a block, they are “paying” the receptionist… (shared or not they contribute in one way or another to the costs) does that mean the receptionist refuses their parcels when THEY pay the wages ? Accepting parcels/deliveries no doubt appear in their contract somewhere ! As such, this makes the concierge/receptionist an employee, either exclusive or shared worker so I would argue that one of their employees acted negligently and so why is the responsibility then down to us?
If they customer is not the boss paying the wages and simply “works” in the building that has a policy of no private mail/deliveries then again, THEY should be responsible for supplying an address that they KNOW can not receive mail (albeit physically mail can be received, they know, by way of their work contract, that mail is NOT supposed to be received and therefor can not claim it was not received, nor complain it was rejected as ignorance is no excuse in the eyes of the law, somewhere, they signed a work contract with that clause in effect)
Hanging up my barristers gown lol, we refunded anyway, we’re nice guys