I wanted to check whether anyone has similar experience in the past and any known outcomes. It appears that no one so far. But I am pretty sure that there is no issue of plan/CAD versions which is causing this issue, as Daniel H raised. We both are refering to one final plan.
Based on all the suggestions, my action plan seems to be
- Talk to the builder first and try to resolve
- If required, avail an appraiser services to determine the reasonable value
if the above option does not work, will look in to the options of
- Legal action in a court or arbitration services.