I assume you did not read the policies and/or frequently asked questions that are posted on NGC's "help center" webpagebefore sending in your coins. If you had, you would have seen this:
"NGC assigns an adjectival NGC Details Grade to coins that have surface conditions that preclude numeric grading. These surface conditions include improper cleaning, scratches and damage."
or this:
"Numeric grades give a strong indication of a coin's value relative to its value in other grades. Most collectors and dealers would pay more for an MS 64 than an MS 63. This is not necessarily the case for coins that have received NGC Details grades." The value of NGC Details-graded coins is much more subjective due to the variety and severity of the surface problems that result in NGC Details grades. It depends a lot on one's personal preference. Some collectors may prefer an XF Details Improperly Cleaned coin to an AU Details Scratched coin, while for others it may be the opposite.
If NGC were to assign numeric grades to coins with surface problems, it might imply that higher graded examples would be worth more than lower graded examples. That would not always be the case, however, depending on the type and severity of the problem. An MS 64 Scratched coin would not necessarily be worth more than an MS 63 Improperly Cleaned coin; it could be the opposite.
To avoid this potentially confusing scenario, we describe an NGC Details-graded coin's condition with an adjectival grade range along with a statement of the primary surface problem".
Might have saved you some frustration if you had done a bit of research before submitting.
If you had read this prior to submitting, you would have known that, in the event your coins were determined to have issues, they would not receive a numeric grade.