My guess is that they had a turbo laying around that failed and thought hmmm let me take this good controller off of this bad turbo and charge for an entire turbo. You can change that without removing the turbo itself, just need to move the alternator out of the way.
When I had issues on my 05, I found a turbo on Ebay that they said was a core, I bought it, pulled the actuator off, cleaned it up and installed it on my turbo and it worked like a charm. Later the turbo blew itself apart and I took the one I bought on Ebay, put the actuator back on and ran it unitl I sold it.
My guess is that the one I bought just had a stuck linkage, once i freed it up, worked fine.
Hope you get your money back from that shop.