Background: I started a PhD in a CS-oriented field about 8 months ago, after completing my masters. At the very start, I was given a lot of duties besides my PhD project, such as responsibility for several of our servers, various software and hardware, user accounts, etc. I also serve as a TA to different courses every semester. After all that, I estimate that in terms of time, 15% of the working week is maybe left for research work. In my project I work alone (this is nice), but my project as well is more ambitious than that of other people, as already confirmed by my advisor and colleagues.
Problem: I started a PhD with the hopes to research an issue at depth and gain expertise in that field, now I find I don't actually have time to seriously devote myself to research activity. I was apparently hired to be some kind of an "assistant", but not one that should be called "research assistant". On top of all, I'm paid much lower than what I could earn out in the open, or what I should be paid given the amount of hours extra I put in. I am really demotivated because I entered the PhD with different intentions. FYI, I have no desire to continue in academia as a career, neither do I need the "Dr." title to be more marketable or for ego purposes or whatever - the only reason was fun of the kind I get very little.
Question: I can't decide if it's worth it to stay, I also don't want to be spoiled and foolish. I won't take your word as command, but would be nice to just get honest 3rd party opinions, or sharing if you're dealing with the same situation.
EDIT: thanks all for sharing thoughts and giving some advice. I marked as "answer" the comment with the most subcomments. I already talked to other PhD students and it seems most don't have it as tough as me. I guess with all these tasks eventually the quality of my research will suffer, and I will talk to my advisor about this particular point, as I believe this should be a concern for him as well.