To the OP your young and to trusting, that's not your fault! You gave the shop your vehicle, cash up front with hopes they knew what they were doing.
Fact is not many shops now days can work on older vehicles let alone turbo cars. Around here alot of shops won't even safety a older car. They scare them. It's a plug and play world.
So what l read out of all this is you took car to a shop, they fix stuff and over charged for the parts, then installed a rebuilt turbo and it wasn't any good, then with his manpower shortage he let yours sit. Just a cluster F...!!
So what can you do? Wait until it's fixed or tow your car somewhere else, as you have said your have limited knowledge. I honestly feel that the shop hopes you will take it out of there!! That's why they are dogging ya.
I also think that there has been some good advice in this post and more than afew guys are willing to help or guide you threw getting your Turbo fixed, as in take your car home and send out the turbo to a place that they only work on turbos.
There are guys on here that can walk you threw every step of removal and reinstall if you decide to go that route.
By the way opinions are like *ss holes, everyone has one, so take it for what they are, people honestly meaning well!!