Dorothy Perkins PPI Account Info Help

Hi
I have been trying to help my wife with a claim she is trying to start regarding a Dorothy Perkins Store Card from the 1990s Onwards but have hit a buffer and would appreciate some help or advice. I initially wrote to Santander PPI Team with all the information we had at the time which including dates, addresses and full names (my wife has been previously married so there was a name change). My wife has no paperwork or documentation regarding this Store Card and some of the dates given were the best we she could come up with but would not be 100% accurate. We received a letter back from Santander stating they had no record on there system of the account. I then sent a letter to Genworth Financial regarding a PPI claim on the Store Card and we have just received a letter back from them stating the cannot pursue a claim without the account number. So my question is?? Is there a way of finding out the Account Number of the Store Card with only Basic Information Available??? Thank You In Advance for any Help or Advice