Other than IVIG for specific cases, the current RX medications do not work to do anything for neuropathy other than suppress symptoms. They do not heal anything.

Here is a link with numbers and discussion about types of bariatric surgery and neuropathy outcomes.
http://docnews.diabetesjournals.org/content/2/1/9.full

I would suggest you get your B12 numbers and not rely upon "normal". Ranges in the US go down to 200 and at that level there can be significant nerve damage. If you were taking something at the time of the testing, the numbers reported may be high for that time only and not reflect other time periods. Going off the vitamins for a few days before testing, is what most people do.
A multivitamin with 200% RDA B12 is nothing (RDA for B12 is typically 4 micrograms so 200% RDA would be 16micrograms. Typical oral B12 is in the 30,000 % range because only a tiny amount ever gets absorbed. Not much if anything from 16micrograms would be absorbed orally)

I know you are frustrated and in pain. This just makes everything more difficult because stress increases cytokines (inflammation chemicals) in the body, which then affect blood circulation, and healing.

Have you tried soaking your feet in epsom salts? This can help and if you do it 2 or 3 times a day, by the end of a week you may see some change in your pain levels.

It takes a long time to heal when nerves are disturbed/damaged. My feet didn't return to a more normal level (absence of pain/numbness) until a YEAR into my thyroid fix. It took that long!

Also I don't recall your saying you have had mechanical evaluation of your feet Xrays, etc? ... Gout, and pseudogout, are possibilities, as are broken sesamoid bones in the ball of the foot, and neuromas. If there are color changes in the feet, and sweating, then RSD is a possibility too. One thing may lead to another unfortunately.. and all have to be considered.