When you have horrible service there's a really great new thing called the internet. I use it all the time! I contact corporate headquarters and report the lack of service.
This happened at one of our local Walmarts several years ago in the paint dept. I had someone paged to help me 3X. I stood at the paint department counter and yelled as loudly as I could "I need help with paint. Will someone please come to the paint department and help me?" (I did that 3x also. My friend and daughter ran each time) 45 minutes with no help. I left and called every 1/2 hr. for 3 hours---couldn't talk to the manager he was in a meeting.
After contacting headquarters the manager called to apologize then got fired.