law: Delhi Rent Control Act, 1958 
  33. Charges in excess of fair rate not
  
  recoverable. -
  When the Controller has determined the fair
  
  rate of charges in respect of a hotel or lodging house, -
  (a) The manager of the hotel or the owner of
  
  the lodging house, as the case may be, shall not charge any amount in excess of
  
  the fair rate and shall not, except with the previous written permission of the
  
  Controller, withdraw from the lodger any concession or service allowed at the
  
  time when the Controller determined the fair rate;
  (b) Any agreement for the payment of any
  
  charges in excess of such fair rate shall be void in respect of such excess and
  
  shall be construed as if it were an agreement for payment of the said fair
  
  rate;
  (c) Any sum paid by a lodger in excess of the
  
  fair rate shall be recoverable by him at any time within a period of six months
  
  from the date of the payment from the manager of the hotel or the owner of the
  
  lodging house or his legal representatives and may, without prejudice to any
  
  other mode of recovery, be deducted by such lodger from any amount payable by
  
  him to such manager or owner.