As far as VAT is concerned, please check with any local consultant as the same is state subject and different states charge VAT on real estate differently.
For Service Tax: The Builder is incorrect in charging the same as the provision for charging ST on 33% of value was done away with in January 2009 and no ST was chargeable since then.
New provisions for ST are applicable wef 1-7-2010 only and ST will be charged @ 10.3% on 25% of amount received after 1-7-2010 only. Electricity Board deposit is not amenity, hence no service tax can be carged on the same. Parking has been specifically excluded from service tax.
As far as amentities are concerned, yes builder can charge ST on preferential location charges, Internal and External development charges received only after 1-7-2010. So if you have made payment till date, no service tax shall be payable.