Phone help

So I just got a new phone because my old one was. . . outdated to say the least. I got a rogers samsung sgh-a766 and i put this one ringtone on my phone through microsd but it won't let me set it as a ringtone. It has an icon of a musical note, kind of like the iTunes symbol while working ringtones have a little speaker. It's only 280k and some of the preset ringtones are larger than that. All the files are mp3s. Also, I had to put the file on through a micro sd card because I use a mac and the software the phone came with for computer doesn't work on mac.

does your phone support mp3 ringtones? if so, then the bitrate might be too high or it might not support the encoding type you used (cbr/vbr).

it supports mp3 ringtones, and how could I change the bitrate or encoding type?

either rip the song again using different settings, or use a converter