My experience
Been there done that. Started trying to get an app processed on October 2nd. I had trouble in the beginning with the Experian interface where they ask you a bunch of questions about old phone numbers you might have had, places you used to live, recent credit transactions, etc. Apparently I got one of the many questions wrong (I think it was a really old phone number I missed) and I failed the identity verification. The site threw up a popup with a "reference number" directing me to call Experian to get it fixed. Silly me, I apparently didn't write down the number properly (should have just screen-shotted the damned thing) and when I called they couldn't identify the reference number and without that, no help.
OK, great. No hurry here, I'll just pop back to the site and get the number again. I log back in the next day and whoa - my identity shows up as "Verified". Great, guess I passed after all. My application shows as "incomplete" so I go back and and answer all the questions again and hit the point where it asks me to verify my identity, so I click continue and it says it's "In progress". You can only guess the rest. Days later same thing - app shows "incomplete", answer all the questions *again*, hit submit, "Processing...:".
OK, I admit it. I'm stupid. I did this three more times over the last two weeks, hoping beyond hope that it was just a systems glitch and they would get it fixed. Well, last night I was done playing. A month had gone by and still no progress, so I did a web chat (that finally worked!) with the oh-so-helpful support folks for the site, and after explaining all of this to them and practically begging for the reference number (nowhere to be found apparently) about 10 minutes later they tell me I need to "mail" them a copy of my driver's license, passport, something that will let them identify me. Oh - and no answer why my profile still shows my identity as "Verified".
I'm sure this will scale well...