Blinker works sporadically

on the newer chevys the turn signals are ran through the hazzard switch on the dash i would start with that its a easy fix to start with

I believe you mean the multifunction switch. If it worked after the initial repair then it was most likely diagnosed and repaired correctly. And its possible its bad again. If the shop that did the repair, tried to save you a little money or make a little more, decided to go with a cheaper part. Sometimes you get what you pay for. But it wouldnt hurt to take it back to them They might still be able to warranty the part back and get a new one but they may make you pay labor again

I agree with everyone. Parts under one year old are still under warranty with all the vendors. Take the car back in under warranty. Remember 2 out of 100 parts are already defective right out of the box. Good luck.