Why have I only received partial amount of my tax refund

same here, i've received 300 of the 1400 i was supposed to receive. 

This happens if you elected to pay your fees for TurboTax from your refund (if the amount of the difference is equal to the fees). 

To check your TurboTax fees, follow these steps:

1. Login to TurboTax.com.
2. Click on Tax Tools in the menu on the left (to see this option, you may first have to click on "Continue where I left off" or similar language).
3. Click on Tools.
4. Click on My Fees in the menu that pops up.

If you did not pay your fees for TurboTax with your refund, or this does not explain the full difference your return may have been adjusted by the IRS  (such as for clerical errors, unreported income, or back taxes), or your refund is subject to a U.S. Treasury offset.

For IRS adjustments, the IRS will send a letter of explanation to you typically within 7-10 business days, or you can call them to inquire at 1-800-829-1040.  This phone line is open from 7 AM- 7 PM in your local time. 

For U.S. treasury offsets (federal debts such as defaulted student loans, certain fines or other federal obligations, and past child support obligations), you may contact Debt Management Services at 1-800-304-3107.

TurboTax is not sent any information about your refund after the initial acceptance notice from the IRS.

@sterling65