The concierge service is available to Prestige, Signature and Platinum cardholders, but the majority of requests come from Prestige customers, who must have a minimum income of A$150,000 ($164,236) and pay an annual fee of A$700.
Signature customers must have a minimum income of A$75,000 and pay a A$395 annual fee, while Platinum is offered to customers with a minimum income of A$35,000 and costs A$149 a year in fees.
In the case of the Britney Spears earring request, the team phoned the production company, who advised that she was mostly wearing Pucci or Marchesa — but they couldn't find any similar earrings from those brands.
They then scoured various Britney Spears fan forums — which suggested the earrings might be Chanel. This turned out to be a false lead, as Chanel had made similar, but not the same earrings.
After more research online, the team eventually found that the earrings were from a small, independent, jewellery store in Austin, Texas — and they only cost US$18.
Unfortunately, the earrings were out of stock. So the team requested they be remade, and managed to source a pair just in time for the woman's birthday.
Wilde said the local team of 30 were "experts" from a range of service industry backgrounds. They receive roughly 650 calls a month, but this doubles in peak periods such as November, Valentine's Day and Easter.
"These people are highly competent in understanding customers' needs, challenging the status quo and also dealing with difficult requests," Wilde said.
"It depends on the time of year, but certainly with the lead-up to Christmas some of the more common things are difficult-to-source tickets, hotel stays, vacations, luxury limousines, gifts for families, really uncommon toys that have maybe sold out in a lot of department stores."
Wilde said last year there had been an influx of calls from cardholders looking for a Hatchimals, while this year saw a flood of requests for tickets to Pink's 2018 concert.
One year, a cardholder simply presented the team with a list of their family members and their interests, and asked them to complete their Christmas shopping for them.
Other bizarre requests include being asked to deliver an elephant as a gift to a temple in India, while one Australian customer asked for coffee to be delivered to his girlfriend who was working in New York.
"The concierge team will go a long way to meet the needs of the customer," Wilde said.
"If something is bordering on unethical or inappropriate, that's certainly where a line will be drawn. I wouldn't say we get a lot — that stuff is just shut down."
