I just have another saturday by myself so bare with me 
by the way, what is your oppinion on this?
I bought two pants from Guess last weeks thorsday and got them tailed by their own service, they told me I'd get them prior to new years eve at friday, or next weeks (this week) monday... but I didn't... and the pants didn't come this weeks friday neither so I have waited over a week for them.
I called there yesterday, they were like; "Oh sory, yeah, it appears we kind of forgot about them in the back of the room we actually just sent them to our tailor just two days ago, they should be ready next weeks monday 09.01, sooooryyyyyyyyy"
I PAID 327 euros for them, why would they forget something like that? What would you do? Just be nice, let it go or give them few words how unprofessional they are for being huge fashion label sales people? Or maby demand a free t-shirt of my choosing or something ?
Not to worry, you don't offend me. I am getting used to your insolence.

Customer service is everything! I don't know what the clothing business is like where you are, but everyone is fighting for customers here in the U.S. Good jobs, especially in the service sector, are hard to find. It seems like they gave you a weak excuse. If it were me, I'd let them know you are really unhappy with their service and I'd probably complain to management too.
My daughter says I am a master at very clearly letting people know they've screwed and I am really pissed about it, while I maintain decorum at the same time. What you want to do is shame them into making this right for you.
Since you've already paid for the pants, getting your money back may be a problem, especially once the pants are tailored (I assume these aren't jeans). Does one get jeans tailored? I wear mine rather baggy (to cover my wrinkly ass, LOL).
Yes I agree, they owe you something for your trouble. A free tee shirt would be good, if that's what you want.