Quality Problems in the iTMS

I've been using iTunes Music Store quite a lot, and have been mainly very pleased with the service. Lately, however, there seems to have been problems with the quality of the songs – this seems to be especially true with Finnish songs. In several of the songs I've purchased, there have been pauses and cut-offs within the songs. I've reported these problems to the iTMS customer service and have received compensation in the form of a refund. However, after reporting the latest defective song, I didn't received a refund but got a free song credit instead.

Says Apple:

We have issued 1 replacement song credit to download the song of your choice. The next time you log in to your iTunes Music Store account, the free song credit will appear in the top right corner, by your account name. When you download songs from the iTunes Music Store, the credit will be used as payment until all credits have been used or have expired.

And indeed, this new icon now shows in my iTMS window: