Dude, I understand the point of a mystery box. But in one breath you say, stop complaining because you got more than the value paid for the box, but in the next one you say, contact Mishka because you got a bad box and they'll fix it. Huh? If the point is "to get a bunch of stuff for not a lot of money," then what is there for Mishka to take care of?
I'm not guaranteeing that anything will get fixed, I'm just saying that the people at Mishka will be the judge on what there is to do - but having too many backpacks or too many t-shirts you don't like is not a valid reason to complain about a grab bag. As far as value, obviously the point is not to receive $101 dollars worth of merch for $100 for the sake of getting your money's worth.
I'm sure there is some sort of logic behind what is in each box - but I don't know it, and I definitely can't judge on that. So if there is an issue with the content of the box itself (as seems to be the case here), best thing to do is get in touch with Mishka directly.