Hi, if you still want to withdraw from TR to PR you could use the application number to file a webform with an official withdrawal request.
I got the refund last year and without an application number, I submitted a webform to request the withdrawal, however without AOR the webform never got linked to my file. I received AOR before Christmas and using the APP# I sent the webform for a second time. This year Feb they sent a letter asking me to confirm my request. I confirmed it and uploaded the document through GC key. Just last week they finally sent me the official withdrawal letter and in my account the APP now shows 'withdrawn'.
Hope this helps. Of course if you want to keep it processing you don't have to do anything. They will ask you for the refunded fees.