A restaurant charged 12.36% of total bill as service tax ? How can it happen ?

I visited an AC restaurant recently, where they are charging 12.36% Service Tax on total Bill amount, however, they are not including VAT.

Is this correct ? As per my understanding Service Tax can be charged only on 40% of total bill amount, i.e. 4.94% of total bill. Also, per my understanding one must register for ST & VAT when the total annual turnover is > 10 lacs, otherwise, its not compulsory.