This week, would you believe, I reveal to you not a case of sneaky pack shrinkage, but of a pack which has actually swelled by 50g.

It’s a curious case, because you’d think the company would go big with this news – as in shouting “Now in bigger pack!”, but no.

The background: in late 2010, the Advertising Standards Authority ruled that the words “Great Value Refill” on the soft pack of Sunlight dishwashing liquid were misleading and had to be withdrawn, because whereas the original bottle contained 750ml of the product, the soft pack contained just 700ml, and therefore did not “re-fill” the bottle.

Unilever complied, and the 700ml soft pack was duly relabelled “Great Value Pack!”

A few weeks ago, Reinette Wilson of Gordon’s Bay wrote to tell me that at her local Pick n Pay she’d seen the 750ml bottle of Sunlight dishwashing liquid on sale for R15.49, while the supposedly great value “same-sized refill” pack was significantly more expensive at R19.99.

“Surely something is very wrong here?” she wrote.

I suggested to her that the disparity was even greater than she thought, because the soft pack was only 700ml.

No, said Wilson, it was 750ml.

And that’s how I learnt that Unilever had decided to increase its soft pack to 750ml – the same volume as the bottle – and re-introduce the wording “Great Value Refill”.

I asked Unilever about the pricing, when the bigger “proper” refill packs had gone on sale, and why this was done with no fanfare.

Unilever said its recommended selling price for the 750ml bottle was R19.99 and the 750ml pouch R16.99, and said it could not comment on retailers’ prices, except to say that when the bottle was on promotion it would be cheaper than the pouch.

And why was the repackaging done under the radar?

“We do not communicate every product launch we make, especially pack extensions; also because of the competitive nature of the fast-moving goods industry, information on certain aspects of our brands, packaging and other marketing issues, is not divulged.”

So there.