I recently booked flights with VN segments via DL and also had issues. In my case, I received 2 separate $8300 pending charges a couple of hours apart where there should only have been first one. I asked Delta to look into the second charge and was told there had been some delay with VN's process and assured me that the second pending charge would eventually disappear. It did, after a week or so. Good thing my credit limit is high, as AmEx said they "could not" remove a pending charge and I'd just have to wait it out.