When I did supermarket shopping I used to get only as much as I could fit into a basket on my lap when I was on my own. On my way in one day a guy asked if I wanted "the" trolley. After telling him that I find it impossible to push a trolley around he brought out one designed to attach to a wheelchair. Seems they'd had one out the back for ages.
It is the same size as the new small ones that started appearing a while ago. Instead of a handle it is open under the front and sprung rods clip on my front forks and away we go.
It is a bit different to this but the same idea.
Feels odd at first as it makes pushing heavier (and more so as you go) and the turning circle is big, but at least I can do a bigger shop now.
Ask your supermarket whether they've got one and if they don't make sure they get one. They can contact Coles at Westfield Bondi to ask where they got theirs.