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Your 24 hour esophageal pH monitoring done once in 2009, Gangaram showed significant esophageal reflux that can explain your symptoms. However if the symptoms were solely due to acid reflux they should have disappeared by now but as per your report they haven't.
The next most important consideration in the cause of your pain is visceral or esophageal hypersensitivity. The best test for detecting this condition is a balloon distention test. (See page 51 here:http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3038318/pdf/GH-07-50.pdf)
I would suggest that you repeat the 24 hour pH monitoring test from the nearest center of your choice and if normal now (due to the Nissen's fundoplication done in 2010) you should be investigated for visceral or esophageal hypersensitivity with a balloon distention test.
Visceral hypersensitivity is a heightened conscious perception of visceral stimuli independent of the intensity. Heartburn is perceived and modified by the central nervous system, a complicated process that is being elucidated using esophageal evoked potentials by electroencephalogram, positron emission tomography, functional magnetic resonance imaging, and other methodologies.
Dr Satish S. C. Rao, Professor of Medicine, University of Iowa seems to have done the maximum amount of work in this area and in this paper http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3038318/ he feels that If an esophageal pain is ascertained as due to visceral hypersensitivity then a trial of Tablet Theophylline may help.
Do keep us updated on your progress an wish you a speedy recovery.