I had once lost shipment (unregistered mail) and once only one dead IC, from what i remember OPA2134.
With shipment lost i received full refund (paypal case) without any problem, fast and of course apology etc.
In case of the dead opamp i just informed seller and with another order, month later, i received extra, working, IC.
Maybe some people had problem with simple communication?!?
I have only good experience with polida.
I newer had luck with exchange of broken opamp in any of my local stores...