Players of Fight Night Champion on Xbox 360 have been reporting problems with lost XP packs (see EA Forums here and here). There are numerous other threads that have been closed or removed as well in what appears an attempt to control the flow of information. After an email came into the GDN newsroom we did some investigation into the matter and found that the problem is rather widespread and that both sides [EA and XBLA] seem to be
blaming each other.
First, a little background. Fight Night Champion, from EA, offer what are called XP Packs. These packs allow you to basically purchase XP which you can apply to OWC boxers. OWC is the Online World Championship which lets you compete against other players. The XP packs are only available through the EA store built into the game and not through the normal Xbox LIVE Marketplace.
XP Packs let you quickly boost your character to a higher performance level instead of grinding it out. They’re basically a time saver which can only be purchased directly through the Fight Night Champion store from the game. This means that EA controls the servers and the transactions. While you are paying Microsoft Points for the XP packs, the transaction seems to be handled by EA. There is some dispute between the two as to who is truly responsible for it all. This is a problem of transparency because when a problem occurs (like now) gamers do not know who to call for help and that is just poor customer service and perhaps needs some investigating by a consumer rights organization.
The problem of XP Packs Disappearing
From the looks of things, it’s an EA issue with the packs being stripped from accounts or not being properly integrated into the game. The understanding is that when you purchase an XP pack and apply it to an OWC fighter, you can then delete that character and you will regain the XP which can then be re-applied to a new fighter.
According to the EA.com forum moderators, who are the only EA-attached people willing to talk about this at all, there are certain things to be taken into account.

The XP Packs have to be assigned to an OWC character. If they are assigned to a Legacy character (that’s local single player) they will not be able to be used on an OWC character. Also, if you assign them to an OWC character of a certain weight class, they can then only be used in that particular weight class (which seems sort of lame to me). Finally, they state that sometimes unassigned XP has to be reassigned from the Boxer Growth screen and may take some time to be applied. No clarification was offered on this statement.