Resources such as credits & packs are tied to the device information such as LAN MAC, Serial Number, IMEI, etc.
Are you certain that the device you unregistered and registered again is the same exact device and not a different one? Any typos as well could mean that the pack won’t be there.
If you head to Administration → Companies → Company details and view the device list (in which your device should be), what is the management type? Does it say “Pack” or is it empty?
If you download the file in your initial post and view the inside of it, I believe there should be a serial number somewhere. Please compare that with what you have and confirm that it’s the same as well.