I500 SMS software

I lost my SPH-A900 phone, and since I didn't want to pay another $350
for a new phone, I bought an i500 off ebay. Its refurbished, but works
great.

However, I cannot send text messages !!! And even worst, I don't know
who text messages me !!! Its crazy.

I did online searches, and apparently I need a software called i500SMS
from pdaapps.com ; the problem with this is that they stopped selling
it there and I can't afford to pay another $50 for a software anyways.

Anyways, does anyone know if they give the software for free anywhere
now?? Or how I can get it?

If anyone has the software and/or retired/upgraded his/her phone, I
would appreciate if you can share your software with me. Email me at:
ashgar1111@yahoo.com