Low memory on my nokia 7600

I first bought my nokia 7600 with the tariff on 3, it had plenty of memory i could upload songs from my computer sucessfully. Then i went to get my phone unlocked and it was then back on 02. But my memory was really low and my phone no longer works with the connection 'nokia pc suite' and even if i do try to download a song from the program it will say 'not enough memory to download file' even if the file is below the memory amount on my phone. with everything from my gallery deleted i can get 982.8 KB. Is there anything i can do? can i buy a memory card? please help.
Can i restore my factory settings? if so, what is the code to do so.

thanks, Gerudo.