Consumer organisation Which? is to make a super-complaint against companies that impose "rip-off" extra charges for people who pay with credit and debit charges citing no-frills airlines as the worst offenders.The consumer group will ask the Office of Fair Trading (OFT) to investigate card surcharges, especially at the point of payment.Low-cost airlines are among the worst offenders, it claims, "with some charging a fee per passenger, per leg of the journey, in spite of the fact that they only have to process one transaction." "A family of four booking a return flight with Ryanair would be charged £40 to pay by card when the cost to the airline would be around 20p to process a debit card payment and no more than 2% of the transaction value for a credit card. The same family would be charged £38 by Flybe and £5.50 by Easyjet for paying for return flights by card."Local authorities, estate agents, cinemas and even the DVLA are now beginning to levy excessive charges for paying by card, Which? added. "There's simply no justification for excessive card charges - paying by card should cost the consumer the same amount that it costs the retailer. Companies shouldn't be using card processing costs as an excuse for boosting their profits," Which? chief executive, Peter Vicary-Smith, said.The super-complaint is Which?'s first since 2007 and will be submitted to the OFT at the end of March.Ryanair dismissed the claims saying its does not levy any credit or debit card payment "surcharges".