I have suffered from chronic heartburn/acid reflux since I was about 10-11 years old. The family doctor gave me handfuls of Rolaids, and put me on a bland diet. In the early 90's, I was prescribed Prilosec, before it was available OTC. Nothing really worked.
I've only had lasting relief in the last few years, after seeing something on TV about how the sphincter that closes off the stomach was triggered by acid, and some cases of reflux were due to a lack of stomach acid, in which case antacids/blockers would make symptoms worse. It was suggested to drink vinegar when symptoms occurred. I tried it; drank a shot glass of apple cider vinegar (Nasty!!!), and about 15-20 minutes later let out a very satisfying and pain relieving belch.

Your mileage may vary, but it's worth a try...