Turbo Issues... Need Help?

[M1308]

I own a 2009 Ford Focus 2.0 TDCi, which I bought used in June 2012. I have had a couple of issues with it, but none more so that what has recently occurred with the car. I took it to a garage which specializes in Remapping cars, I know the guy who was working on it. Anyway, at first there was an Error Code for a DPF related issue which caused my car to be stuck in Limp Mode. Now, I got my DPF removed and still it was in Limp Mode, so he put on another piece of Software which after tweaking, eventually took it out of Limp Mode and made the car drive(able) again. However there was an issue and the car wouldn't make boost. At first we thought it was a Vacuum Line from the Actuator, which it turned out not to be. Secondly they thought it was the Pressure Converter, but when replaced we found that didn't do the trick either, and now we think the Turbo is on the way out. Now it's not a definite that it is the Turbo, but I need to know firstly, what kind of Garrett Turbo my car has got, and secondly how much can they cost to buy and get replaced? Also, any information on what you think may be the case would be very appreciated!