What he can do for you right now is ship the PCBs assembled excluding the chips DUE TO YOUR INABILITY TO PROVIDE SAID CHIPS and keep all the money.
Maybe he should add shop product "assembled pcb without chips" and put price for it. If customer don't send chips in reasonable time he can downgrade order and refund rest? Should fullfit EU laws. He sends something. There are maybe some EU return policy which may complicate things?
And there are maybe customers who are interested to buy assembled board without chips + suitable (mylar?) stencil to add chips at home..