Boys AT Rifle Not Retaining Level Up

After the May 23 patch I've played a number of games to try to upgrade my Medic EMP from level 3 to level 4 (I am a relatively new player, hence the low levels). I have played games wherein I have leveled the gun to level 4 (as shown in the accomplishments messages after the match ends) at least three times (that I know of, I might have missed some).

After the first two games, I quit to go to my weapons management on my Medic, but when I got there, the gun was still level 3, and I could not purchase the last upgrade.

After the third time, I stayed in the matchmaking, choosing continue instead of quit, and went to upgrade my weapon in between matches. Now I could purchase and unlock the last weapon specialization. However, when I eventually quit playing and went back to my character, the weapon had yet again reverted to level 3. Unfortunately, I did not check my CC balance, so I am not sure if the payed amount for the last specialization (CC 750, I believe), had also been returned or not.

I have restarted my game several times, but the weapon is still on level 3.

I am in the EU region, and the time frame in which the problem occured should be somewhere around 16:00 - 18:00 CEST, or thereabouts.

Cheers,

/inglorious