Originally Posted by MichaelA380

Have you checked whether the hotel perhaps applies a minimum stay duration (that may be the reason why you see no reward availability for the shorter period)?

I am a bit puzzled by the information you received over the phone though - but I wish you luck, I hope they deliver on what they told you.

In theory, while you should not be able to shorten the booking, you could depart early and request to be released from the remainder of your reservation (and receive back the points used to pay for those remaining nights) against paying a penalty fee - have a look at your reservation confirmation, under the section Other Charges there should be an Early Departure Fee mentioned, that would be your penalty should you wish to shorten your stay.