I received 900.2$ instead of the 970$ I was expected to receive how do I collect the rest of my tax return or refund

If you chose to pay the TurboTax fees out of your Federal refund, then the following likely explains it:

TurboTax fee 29.99 (could be either a state return or a PLUS upgrade).
And the option to pay out of the Federal refund has a 39.99 service fee.

That would total 69.98.  

$970 - 69.98 = 900.02.   Was your refund 900.02?    You typed "900.2" above.