Hi there! I'm sorry that you have to go through all that during your stay at Crowne Plaza in Australia. You have all the right to feel this way.

Here are my takes on the issue:
1. You need to recognise that Crowne Plaza is primarily a business hotel. The fact that the hotel had even bothered to write a card for your friend and provided a bar of chocolate is already exceptional in itself. If you're expecting something more than that, I would recommend that you stay at an Intercontinental hotel instead.
2. Gold Elite status with IHG holds no value at all. Even holding Spire Elite (top-tier) status at a Crowne Plaza gets you practically nothing - no free breakfast, no free club access, no free upgrade to a suite (with the exception of Crowne Plazas in greater china and some parts of Europe where you do get complimentary lounge access and free breakfast as a welcome amenity). At most, Spire elite members can expect a one-category upgrade to a higher floor or better view. That's it.
3. The series of issues that transpired is definitely unforgivable. They should award you compensation. Hence, I would suggest you write to the GM of the hotel detailing the issues that had happened and perhaps ask for 20,000 IHG points as compensation for the entire situation. With the dynamic point rates in play these days, it will be quite easy to burn 20,000 IHG points at a property in Australia. If there is no reply from the GM, then write to IHG Customer Service although I wouldn't expect much from them. Leave them a negative review on Tripadvisor should all else fails.
4. Before your next stay at an IHG hotel, I would strongly recommend that you purchase the Intercontinental Ambassador membership that comes with IHG Platinum Status (which gives you more benefits like a room upgrade and late checkout). The Ambassador customer service (via email) is more helpful and forthcoming than the generic IHG customer service email. No matter which brand you stay at and when you encounter a service lapse, they are always very helpful and will usually provide 10,000 IHG points as compensation. But again, please do not abuse the system by complaining after every stay. Some loyalty programs, like Hilton, ban accounts for complaining too much.