Why does global shipping scavenge & seize the hard earned negotiated deals you purchase?

[michaelg38173]

Bought a magnetic therapy mat for my terminally ill dad who suffers & hardly sleeps. This deal took months of searching & weeks of organizing just to have the shipper seize the medical device & inform it would never be returned as it was to big to ship (only 500mm long x 500mm wide x 200mm high), it cannot be returned to the seller or sent to my original shipper that I requested but they would buy it from the seller & auction it off. This is nothing less than theft as I did the negotiating & the seller who had a good heart & halved the price due to the fact it was a medical device for a terminally ill ex pat who served in the war. The seller was very concerned ttthat the shipper Pitney Bowes seized the device preventing a man in desperate need of it from receiving it, the shipper smuggly informed the seller "Don't worry it will go to a good home".  Would love to hear some legal advice to shut down this form of scavenging. Thanks Michael.