The only thing you can do is to prepare, print and mail an amended return form 1040X. To do it using TurboTax, you would first have to recreate the tax return as you originally filed it. Since you apparently don't know why the two returns are different, it would very difficult for you to recreate it in TurboTax.
It is highly unlikely that two different tax preparation companies would result in different refunds. You need to look at what you entered into each program very carefully. You may have made a mistake in one of them.
