Whilst you correctly advise details about heavily discounted rates are not eligible for points under PC Rewards (from Section 11 of the Terms and Conditions), you may not have taken into account the line (bolded) from the following quote of Section 11:
Eligible Charges Worldwide include the following Qualifying Room Rates paid for hotel room nights: non-discounted rate, standard corporate rate, worldwide sales negotiated rate, national/regional/local government rate and specified leisure rates as confirmed by IHG's HOLIDEX® Plus reservation systems. Points will be awarded for Qualifying Room Rates booked through IHG central reservation offices, IHG web sites, travel agents or directly at the hotel. In addition, in North, South and Central America and the Caribbean, points may be collected on locally negotiated rates if these rates are discounted less than 30%. At Asia Pacific hotels, Qualifying Room Rates also include all locally negotiated rates.
The stay was in an Asia Pacific property (property name is in the Asia/Pacific region). The Entertainment Card rate is a locally negotiated rate (only 10% discount from the regular rate).
Please cease my invonvenience by correcting the mistake in the system and crediting me with the 2 night stay and relevant points for the expenses incurred.