Here is the message Hilton sent to me on this problem:

Thank you for contacting Diamond Special Services.

A computer glitch resulted in some member stays being posted with no points and miles. This has been corrected and the points and miles, if applicable, have been awarded. We apologize for the delay in posting your credit and for any inconvenience and confusion this may have caused.

If you have any additional comments or concerns, please feel free to contact the Diamond Desk.