dont know what the situation is now under full deregulation but any of the major gas marketers could hook folk (small businesses and large houses) up to the Transco grid in the phase before all residences came on - and we did it far cheaper and quicker than BG - no compromise on safety as, in my case, the Co was owned by Shell and Exxon.......
Would have thought if it was a bona fide supplier with certified engineers, this could be done outside BG's domain