Have you not tried British Gas on the following number
( switchboard ) on 0113 3821022 and asking for whatever section / department you require.  You could even try this number: 0116 2502000 ( switchboard )

The worst, that they will do is possibly bite your head off, however I do believe, that either number they will be only too pleased to put you through.  Whenever I need to phone BG Servicecare to call out BG for a boiler fault  ( very infrequent ), the lady at BG puts you through with no problems.  Remember, if you do not try, you do not get.

Cheers.

James Bond