I am having problems w/ my chocolate.

I have a t-moble one but I dont know if its any different from verizon. I put some mp3's into my phone and tried to use them as a ringtone. No matter how many times i set it as a ringtone it wont work. If I go to groups and set a ringtone for the group then the mp3 ringtone would work, but only for the people who is under that group. I would like to set it to default but its just not working. I would also like to know if theres any way to store more than 20 numbers under one group or not have any group at all. I dont want the icon next to the names on my phonebook. Is anyone else having this problem? or Does anyone know how to fix any of my problems? Hopefully someone can help me.
Thanks a bunch,
Amy