Right okay. Try the following methods.
Method 1) Take the memory card out and attach it to your computer (if you havent got the right sized card for the computer, get a memory card reader for about £1 otherwise you can do this by plugging your phone into the computer using the cable you got with the phone, sometimes you have to select an option on your phone to allow it to open the memory card, simply read the manual for assistance) and copy all your music, videos etc from it to your computer and format it. (this can be done by going to "My Computer" and right click your memory card icon and select "Format" - this will delete everything but you have already copied it to your computer so you dont have to worry, just copy it all back when it has finished.
Method 2) If you have done the last method and it hasnt worked or you simply dont want to use this options, try downloading the Opera Mobile Browser from getjar.com, open the internet on your phone and goto this address: m.getjar.com and type this code in the box if it asks: 3334 - you will be taken to the place to download Opera web browser. When the download has completed, it will be saved as a game or an application, open Opera Mini Browser that you download and goto the page where you download music (Verizon) and try downloading, sometimes its the phone that doesnt allow you to download, not the memory card.
Plug your memory card into your computer and when it pops up with your memory card, goto www.beemp3.com
and download the music you wish to listen to and copy it to the memory card, you now can listen to the music you have downloaded.
It seems your memory card is fine, the service that "Verizon" is giving you is not working properly. A license doesnt interfere with your memory card but it does with the website. My best conclusion would be that the site isnt working properly for you and anything you try to do will not work as all your hardware is working properly but the Verizon site isnt allowing you to download, this could be caused by your type of phone, the amount of downloading. It could be millions of reasons so i would recommend arguing the hell with Verizon and saying your memory card is fine (if you can access the files on your memory card, theres nothing wrong with it!!!) and that the service isnt working. If they dont do anything, just do the second method, this will allow you to download ALL the music you could ever want for free and you can just copy it onto your card. - if you need ANY help what so ever, dont hesitate to email me at firstname.lastname@example.org
Hope this helps,