Hi
We understand your point of view and it is highly sad that builders (especially gated community builders) have scant regard for following lay out and building plans resulting in water seepage inside villa's.
Legally you can claim refund of money given that
a) Builder has not handed over possession and
b) faulty/ irregularities in lay out design resulting in water seepage in to the villa.
Water seepage in to the villa comes under category of negligence vide 2(o) of the consumer act and hence considered a tortious act.
Option 1:
You can file complaint against the builder under Section 31 (1) of RERA Act and also make an application for investigation in to poor quality of lay out against the builder vide section 35(1)(4) of the act.
Option 2:
You can proceed against the builder under Consumer Protection act u/s 2 of Consumer Protection Act for negligence, defective goods, deficiency of services or hazardous goods or service
RERA in our opinion seems to be working faster, given that RERA is specific to real estate whereas consumer protection act encompasses all consumer related issues(medical, travel, reality, insurance etc) and also that there is a huge backlog of cases at all consumer forums.
Also , given the fact that RERA has investigation powers (unlike consumer forum), approaching RERA may be beneficial in your case.
Hope this information is useful.