My wife had the procedure and personally, I hate it. However, to answer your question she has not had any pain issues with the device. If there is any scar tissue adhering it to the wall of the stomach it may be stretching that tissue as your stomach swells or shifts. Nobody on this forum can tell you if in your case that's true but I would insist the Dr. explain his answer and address the issue. Perhaps the Dr. can adjust the band, it may be too tight. How many times has it been filled? Also depending on your size (layer of fat) the port may be more/less visable. My wife's port is palpable but not visable and she's lost 80 lbs or so.
Hope that helps.