RE TRANFER FROM DLA TO PIP.

hi there i too have just got the dreadd brown envolope to start a claim for pip..i was asked on the phone if i wanted them to use my past dla information to help with my claim for pip,,i thought well it carnt hurt so i agreed,,but today i get a letter stateing that there was no evedence to look at have i got anything else i need them too see..so i phoned them and i was told that becouse my dla was for an indefinate period they dident keep any information,they get it read it and dispose of it ,,apparantly..now iv never heard of this before now,,has anyone else heard of it,,so now in having to dig back yrs to find info of the claim they have been paying me for over 16 yrs,,its ridiculas,they said they had something from 2009,as if,,,i never expected that..so i dont see how they can do that