Acrylic nails falling off after only 1 week

I am extremely disappointed that you can pay so much for acrylic and/ poly gel nails & within a week they start chipping or completely popping off. I will never go back to Sorbet. I have tried 3 different salons in the Northern suburbs of JHB over the past 6 weeks & the quality of their products are exceptionally bad. Every time they offer to re-do my nails free of charge, but it never lasts past just one week & acrylic is supposed to stay on for at least 3 weeks! Strangely enough I never experienced this problem at the Greenstone branches, but the salons in the Northern suburbs is not up to the same standards. I have been a loyal customer for many many years, but sadly it is time to change to another supplier now.