This is correct.
When you start
the amend process, the refund that is shown in TurboTax is reset to zero.
You will still
get the original refund if you were due one based on your original tax
return. The amended return will show the difference you owe, or that you
will get back as a refund. If you are due an additional refund based on
the amended return, it will come separately in the form of a paper check.
3 weeks after you mailed your
amendment, you can start tracking its progress at the IRS Where's My Amended Return? site.