Is eBay's Global Shipping Program a scam?

If you Google the title of this topic you will find some interesting posts by dissatisfied eBayers.
I have only had two experiences of this “service” and both times my experience was less than satisfactory.
The latest purchase was with a UK seller. I bought a secondhand camera for £13.59 plus £11.94 for “International Priority Shipping.” When the item took 11 days to arrive, I became suspicious and decided to compare with Royal Mail’s service. According to their website, a parcel weighing less than 250 gm could have been sent for £4.05, with a target delivery time of 3 - 5 days and compensation up to £20. Someone seems to have trousered £7.89 for providing an inferior service. Final delivery was made by La Poste anyway.
This set me thinking about a previous experience when I bought a rather more expensive camera from a seller in Texas. IPS calculated that this would be subject to TVA and deducted the relevant amount from my PayPal account. Now my experience of dealing with the revenue is that they often use discretion and could decide not to charge duty, especially if it is a secondhand item traded between private individuals and the amount is comparatively small. So how come IPS appoints itself tax collector on behalf of the French Government and why didn’t I get an official receipt showing that the revenue had actually received the money?
IPS seems to be jointly owned by eBay and Pitney Bowes.
What are they playing at? Has anyone got a similar experience to share?
As for me, from now on I will not be buying from anyone who uses IPS.

I also had issues with Ebay/ Pitney Bowes, I ordered something from the UK with international shipping, looking at the bill I found they had added ‘Duty’ to the shipping cost. I complained to both Ebay and Pitney Bowes eventually got a refund. It does pay to check the bill. You have to be careful with shippers, fortunately the retailers I use online, Hobbyking, Banggood etc etc give a choice of shippers, I usually choose HonKong post and avoid people like SCS or UPS when buying from abroad as they send a separate bill for customs duty. Generally French customs don’t charge if goods plus postage is less than €100 although offhand I’m not sure what the tax free threshold is. Also some items are exempt ie warranty returns, gifts zero value goods. Just found a good guide here…