Stone walling on terms and conditions

I received an order from Pick 'n Pay online grocery delivery service. The delivery guy was in a rush and we obliged by signing the invoice without checking it in detail first. In checking the invoice whilst unpacking afterwards we discovered 14 items missing (R1000.00 in goods). The next morning my wife phone PnP online, only to be stonewalled by the call desk. They are simply not willing to even look at the issue as the invoice was already signed off. My issue here is around PnP not being willing to go the extra mile to try and assist us with this issue.<br> Process is process, yes. But I feel there should at least be an attempt to assist the client in a situation like this. Furthermore, expecting the client to be solely responsible for the inventory check is also not on. Sign-off should not be allowed by the driver doing the delivery if this is the be all and end all of the process.