I used 3D systems for some prototypes two years ago. I eventually found the name of the company they shopped the work out to in China and started using them directly. I did this because the finished product was very good (mostly CNC work), and 3D systems couldn't find enough ways to screw me up.
They shipped my parts to a competitor - TWICE. After I had a complete fit over it the first time, and got the strongest possible assurances it would never happen again, and how horrified they were at the mistake, they did it again. Then, some time later after I'd stopped using them, they shipped me parts for a different company.
On one of my orders they charged my credit card twice, and when I tried to explain to their accounting manager that they couldn't just process a credit, they had to actually reverse the transaction or it would incur several hundred dollars in exchange fees - USD to CAD - she asked me what CAD was. Now, many of you could be forgiven for not knowing the standard 3 character banking codes for currencies (USD, GBP, CAD, EUR, RMB, etc.) there is NO excuse for a senior manager in their accounting group to not know them.
Good quality work when I got it, and they were VERY convincing when they apologized - I gather they have a lot of experience.