Noni,
I'm very sorry you're friend was not reliable and trustworthy and your tree has suffered because of it. As rock said, relax and think.
The sad reality is whether you want to hear it or not, your tree may very well be dead and if so, there is nothing you can do to change that. Sorry if that sounds harsh but it is the truth.
However, I have a juniper mallsi that I bought last year that was labelled as an indoor plant and I mistakenly put it on my desk at work. About 2 months later I went on vacation for a week and asked a coworker to watch over it which she did dutifully. Despite that, when I returned from vacation, the tree had drying foliage all over it and just did not look well at all. I began searching the internet about bonsai and discovered that junipers are not indoor plants and need to be outside so I took it home and put it outside and watered it when it needed it. To my surprise and happiness, a couple of months later, it began to push out new green foliage and now is pretty much green all over again.
I was lucky. I caught the problem and acted in time. Something you couldn't do because you were away.
Junipers are pretty resiliant. Follow the suggestions mentioned here and give your tree 3-4 months to see what happens. If no new growth happens then, I'm sorry your tree is gone.
As painful as it is, take it as a lesson learned. Get another tree and find someone more trustworthy or come up with a better alternative.