Poor glases quality

I bought my eye glasses from Nu-sight in parow...today it breaks again for the more then 10th times...I've decided not to pay any further coz how van I pay for sumthing that keeps on breaking every second week..they've decided to hand me over and now my bill is 2200 from 1500..how can I pay for glasses that keep on breaking then I have to fix it at other optometrists? It's unacceptable