sansa clip+

i am having an issue with my mp3 i just recently downloaded some songs and started my mp3. i noticed the micro sd card wasnt in so i put it in realized i forgot to turn it off first, turned it off and back on. however when i turned it back on and went to the next song these weird numbers and letters just randomly came out so i shut it off and re did the sd card. now to my problem my sansa clip plus just deleted at least 400-500 songs by itself and all the songs were in my internal memory and idk how to fix it any ideaa?

You might also first try a simple reset of the player by holding the power button down for 20-30 secs, releasing, then pressing again momentarily to start it up. With any luck, it will start up normally. If not, then re-applying the firmware and/or formatting as suggested might be needed.