Basically, the issue is that the merchant (in my recent case, the Rimowa retail store) partners with a tax free facilitator, such as GB. The merchant created a claim with GB at the time of purchase and provided me with GB-specific paperwork that’s intended to be submitted to GB after being digitally “stamped” at the DIVA kiosk. My refund came directly from GB, so I’m guessing they front the money and work with the merchant behind the scenes to get the full amount (probably minus the merchant’s cut for using GB. Nice little system!)

You can’t use the paperwork to get a full VAT refund from the merchant, and as participation in the program is voluntarily, I don’t think you’ll get much cooperation from the merchant with regard to refunding your full VAT, especially if you don’t know your way around the system (I certainly don’t!)

Anyway, I got my cabin suitcase directly from Rimowa a few days before departing, after nearly getting pickpocketed. The DIVA kiosks at BCN were swamped due to the post-conference crowd at the airport (I spotted at least a few new Rimowas in line)