IMHO, unless you can find an employer willing to buy your master's degree for you, don't get it. Degrees are pretty pointless anymore because everybody has them, and employers won't hire you with a master's degree if they don't absolutely need to because they'd have to pay you more for having it. Since employers are such spoiled, cheap bastards anymore, they'll cut corners in every possible way, including turning down a job candidate with fantastic work experience and an advanced degree in that specific field for a schmuck who hardly knows what to do that has an associate's degree in a vaguely similar field... all because less money.
I don't know, maybe my opinion is biased because I'd give my left tit for a boring job right now, and my master's degree has gotten me a whole lot of fuck all as far as
any employment, not just in my field. I'd say stick it out at your current job a little longer and see how it goes, and maybe audit classes in the field of study you're looking to get a master's degree in to see how you like it without committing to full enrollment. Find out if you absolutely need a master's degree for the career you're going to pursue, for starters. No sense getting a pointless degree, especially if you get a job that won't allow you to properly pay for it.
Your current job sounds like my old call center job in regard to the employees. I think I was honestly the only person in that whole office who didn't have a criminal record. I was also bored to tears and suffered stress-induced stomach problems, but that was mostly due to management.