Under the Montreal Convention BA or other airlines are not obliged to offer compensation they will only cover cost of temporary replacement of essential items or cover the loss of them if they never turn up to a maximum of approx £1500.

Out of pocket expenses such as taxis are considered ex-gratis and if BA Holidays promised then imo BA Holidays should honour it as they can’tcompel Qantas to pay for taxis,

I found this out when BA would have paid £80 for a pair of trousers, shirt and some underwear but not refunded £30 return taxi to cover the cost of taxi to airport to get back.