Claimed that packages were never received

I sent 2 well wrapped packages to Gadgets4everyone one whose quotation was £57 the other £36, the larger package had the printed address label on. I obtained proof of posting which has been presented to both the company and the Post Office when it became clear that neither package had allegedly been received. I have put in a claim to the Post Office who have referred me back to Gadgets4everyone who have said they would support me with my claim but then give no indication as to how they will/can support me with my claim. I do not understand how 2 separate packages can go astray in this way and clearly obtaining proof of postage is a complete waste of time. I am totally dissatisfied with my experience and will not be using Gadgets4everyonen again.