Loss of Passport when send to High commision of india,London

Hi all,
I am having bit of problme where i send my 5 year old daughther's passport for renewal to HCI,London by post and now after 4 weeks they are saying that they don't have record of this application.
Looking at royal mail tracking it confirms that it was deleivered to high commision on 06/10 and received and signed by Buntlix Willy but HCI keeps saying they don't where abouts of it.

We have trip plan to india mid of dec and now i am panicking what can i do..
Have any one been in this situation ?
Can anyone suggest what can i do so that they can do the travel ?
please advice..

Thanks,
Deep..