One morning this week, a Brisbane woman took her young granddaughter to Woolworths.

Just inside the door, the woman handed the toddler one of the free bananas Woolworths trumps as part of its in-house marketing campaign.

And as she filled her trolley, her granddaughter helped herself to some of the soon-to-be-purchases – two strawberries, and a big handful of blueberries.

At the checkout, her granddaughter requested a grape.

“I gave her one, reminding her to chew it,’’ she told her local Facebook community hours later.

After the grapes were weighed, the attendant told her that the grapes were “not part of the free fruit’’, and she was now unable to weigh the single grape her granddaughter had just consumed.

“I apologised and handed over approximately $105 for my purchases,’’ she said. “It was only after I got home that I realised I had been accused of stealing. The more I thought about it, the more upset I became. It was one grape.’’

She returned the same afternoon, wanting to pay for the grape – but was told it was not possible to charge her, because a single grape would not register at the checkout.

That grandmother has vowed never to return to Woolworths. And while many on Facebook were quick to remind her that the unpaid grape did amount to ‘theft’, the story demonstrates why our big two supermarkets are now subject to a national pile on.

Rarely do you have city and country folk, politicians and voters, and shoppers from every single generation all on one side, with a single target in sight.

But supermarket cowboys Coles and Woolworths have brought this on themselves with an indecent focus on winning, at the expense of so many others.

Perhaps they would fare better at another time, but their selfish antics – from price disparities between the farm gate and supermarket shelves to accusations of trying to put ‘small’ grocers out of business – stand out at a time when so many of their customers are struggling to feed their families.

Their daily control over us – at petrol stations, the bottle mart, and even pet insurance – increasingly looks like a crass corporate takeover with two winners, and millions of losers.

And their bully-boy tactics – as evidenced by claims that 40 per cent of fresh produce is rejected by the big two – run counter to the corporate decency we are seeing in other sectors, where businesses are raising money for the homeless, and holding fundraisers for domestic violence victims.

The problem is that this dishonourable duopoly doesn’t seem to care that we don’t like them.

They know that many of us, despite despising their treatment of our farmers and the nose they turn up at authority (their CEOs snubbed Queensland’s supermarket inquiry this week), will continue to find our milk in aisle three and our toilet paper in aisle seven.

They know politicians are unlikely to legislate in any way that will really hurt them.

And they know that despite our protestations, most of their customers are unlikely to leave the fold.

That makes us the problem, but perhaps part of the solution too.

How would they respond to an orchestrated and truly grassroots mass evacuation of their customer base?

How would they deal with seeing their customers queuing at the local fruit shop for their weekly fresh produce, filling their cars at independent suppliers and going in search of a new butcher?

Not just tomorrow, but next week, and next month.

At the very least, it might prompt them to look at their own wolfish behaviour, and less at a hungry toddler caught eating a single grape.