I've only ever seen a 10,000 point offer from Liquorland and it is generally over a 3 week period on two occasions. I am on one right now as are a few others reported in recent posts on this thread. The other was a few months ago I never was offered but saw on this thread some others were lucky enough to get it.
First Choice generally only do a maximum of 2k bonus points but I've occasionally seen 3000 or 4000 but that is when you need to spend hundreds.
Regarding the timeline, I don't have any record of First Choice offers that cover the 8th July, but I do have one sent on the 29th June valid until 5th July for 2k points when spending $50 with the Promo code "2000". It could be that or you may have received a different targeted offer you used on the 8th July.
I also had a look up thread around that period and looked for offers matching what you said and didn't find any, however I did note on post 4796 on 4th July you posted the below in italics in a conversation we were having, so perhaps the offer I suggested above is the one you should be entitled to.
Perhaps give First Choice a call claiming that as being the promotion - if it is not the case they would correct you as to the correct promotion if you feign some vagueness.
Good luck!!
Do you take screenshots - I did one with First Choice the other day and have no record of the fact I was supposed to get 2000 bonus points