Revert

re·vert:
intr.v. re·vert·ed, re·vert·ing, re·verts
1. To return to a former condition, practice, subject, or belief.
2. Law To return to the former owner or to the former owner's heirs. Used of money or property.
3. Genetics To undergo reversion.


So if someone asks you to "revert" to them, you can return whatever they have given you, back to them, in the original condition.
And if someone asks you to "revert back", then tell them simply you cannot because the laws of nature prescribes that one cannot turn back the clock.

Fantastic!