Question

customers have complained nearly continuously about the long

Answer 1

and disgruntled workers at the store. =以及小商店里心情不佳（爱发牢骚）的工人

customers have complained nearly continuously about the long lines=顾客们一直不停投诉（抱怨）有关大排长龙以及小商店里心情不佳（爱发牢骚,工作不满）的工人