Poor service

on friday the 26th of february 2016 i went to NITRO TYRES FITMENT CENTRE to fit a set of my own tyres on a set of rims i gave them to fit and balance. so now i drive my car and the wheels are shaking at 60km. then i have a look at the wheels i see that the wheel balancing weights are skew on the one rim. now i went back to NITRO TYRES FITMENT CENTRE and the guy tells me how do i know it is the wheel balancing then i showed him the weights are skew on the wheels so he tells me who is going to pay for the weights.