Hi anyanka,
I'm afraid not, regrettably as indicated in the other post your builder choose to save money by getting the gas mains and meters installed by, what is called, an IPGT - Independent Public Gas Transporter - Independent Pipelines is just one of them. Basically your builder would have put out to tender the installation of the mains and meters. Transco and the IPGT's would have submitted quotations and in the interest of saving them money they would have choose Independent Pipelines.
What happens as you have discovered is the builder saves money, but the IGT's levy their charges for transmission of the gas throught their pipelines to the supplier, who in turn levies this against the customer.
Most of the big six suppliers levy this charge and you will be free to change to which ever supplier you choose, however, this daily surcharge would probably be charged.
Regrettably there is no way you can choose your gas transporter, like you can choose your gas supplier. So you are stuck with this extra daily charge, unless, you change supplier. As mentioned most charge, but I believe, Scottish & Southern dont. But you must ask them before you make any contract, as them if they charge the daily IGT charge.