New turbo installed question

I recently punctured my oil pan and despite stopping within a couple hundred yards my turbo was wasted. I have little faith in the shop that installed the turbo, and now they are going to have it again. Since the new install, 1) the powerband has shifted higher from about 2700-3600, 2) I now hear the turbo thru that entire range, 3) don't seem to have as much low end power (i.e. 1300-2000 rpms), and 4) now the engine runs but seem to have lost the turbo.

Any guesses as to what these symptoms are caused from? Any suggestions as to what I can have the shop start on? And yes I know, I need to find a good mechanic! Thanks!

Chap
2003 New Beetle TDI

Improperly adjusted vacuum actuator on the VNT mechanism would be the first guess. The actuator should start to move at 3-5 inHg and hit the stop screw at 17-20 inHg. DO NOT ADJUST THE STOP SCREW - only the actuator rod itself.

If none of this makes any sense to you or your mechanic - find a different mechanic. There are quite a few good ones "out east". Someone will chime in on who is in your relatively local area.