Had similar with a stay and emailed Diamond Desk with all my details. Quick response, but denied as they stayed it was booked through Expedia.

Followed up to say it was a points reservation through HHonors.com and reiterating the confirmation number and offering to forward the reservation as proof. Had another reply saying they checked and it was Expedia, so there was no point in forwarding it on.

3rd email with the reservation attached and a screenshot of my account was sent, only for another response basically telling me to hit the bricks as they had already confirmed it was through Expedia.

4th email was one asking to escalate to a manager as clearly something was not coming through properly on the system. Finally had a response apologising for the previous service and confirming everything and applying the stay credit and the points for incidentals.

It really shouldn't take 4 emails to the Diamond Desk with all of the right information to perform a simple task. With more stays seemingly not posting properly, I can imagine they are busy. Spending a few minutes reading and checking would be preferable to straight up refusal to investigate and copy and pasting the eligible stays information.