EDIT 5
HOOORAY!
This was patched a day or 2 ago. I thought i had updated both solutions that were previously glitched but my phone must not have sent the edit thru.
/EDIT 5
EDIT 4
http://forums.xbox.com/xbox_forums/xbox_support/xbox_mobile_...New complaint in a new location. Shockingly
they also are unaware of the issues that have been complained about for 6+ months.
/EDIT 4
EDIT 3
Just heard back Feb 3 2015
"I've seen your messages & I can assure you we are still working on it. It's a high priority for us but it's a difficult bug to track down and fix where it will also retroactively apply."
Fingers still crossed
/EDIT 3
EDIT 2
Apparently as of yet no progress has been made.
https://twitter.com/izret101/status/549989395227750400/EDIT 2
EDIT
Got a response
https://twitter.com/izret101/status/541433482489372672/EDIT
As of now (i believe the game is ver 1.02) this achievement appears to be unobtainable.
I completed the collection from Italy on the phone and got nothing for it.
I only have 3-4 collections left to complete so i am hesitant to test more in case this and
don't end up getting patched to sync. I would caution others to make sure they also leave 3 or more incomplete collections in case it ends up being required.
One person has both achievements unlocked so i would assume they got it on an earlier prerelease build.