Amazon and other companies may have just outsourced there payment gateways and payment stuff - Maybe this helps#
http://www.ptieurope.com/about/index.html
&
http://www.ptieurope.com/products/soft/index.html <--- Seems to be the one of interest
Why are people so quick to jump to conclusions - maybe if you rang them FIRST you would know exactly what they do - Or try Ringing Amazon - It's really not that hard to be honest!