Let me clarify the rule position. A dog must be entered in the name of the owner who is giving the entry. In other words one cannot enter a dog on someone's behalf. So it is not possible to enter in the name of the previous owner. In your case the previous owner can enter the dog and give your address and other details as C/o.
As regards the validity of a CC or any other award in the case of transfer of ownership, DoggiesDude has got it wrong. The CC is awarded to the dog not the owner. Therefore, the award remains valid even if the ownership changes. How else do you think we are able to import Champion dogs and retain their international titles??????
Further, pestering never gets you anywhere. Once KCI has responded to your enquiry/application it is upto you to comply with their requirement and get your case processed.