Sony

I just recently purchased a second hand phone from this phone shop.Its a class phone.It has everything i need and everything i wanted.
Now the problem is the orginal owner loaded a bunch of songs and put a lock on the phone.So if i want to format it or master reset(which i really want too) it i require to punch in the lock code.There are a few songs which i couldnt delete from the phone , i tried manually too.But it wont delete it jus stays there.Weird.The previous owner is in another country and will come bak only in 3 months.Is there a solution for this.Are there any unlock codes to do this.