In fairness to QVC the VAT reduction is not due to take effect until tomorrow.
All that the larger companies are doing at the moment is having a 2.5% sale as until tomorrow the VAT they pay on all purchases is still 17.5%.
The basis of VAT is a sales tax, so all retailers pay VAT on their purchases (or when they import the goods) at 17.5%. they then charge the purchaser 17.5% of the total selling price and when they send the 17.5% off at the end of each accounting period, they deduct the original 17.5%.
That's how it works.
Until tomorrow, the government will still demand its 17.5% on all sales.
As our software and accountancy systems are set up to deal with VAT separately (and you see the amount of VAT charged on the invoice - as by law you should do, the best way for us to do it, is to reduce the price accordingly from midnight tonight, which is what it has all been set to do.
QVC are a huge, reputable company and I have no doubt that they will reduce the VAT charge appropriately.
I think it is a bit unfair to complain they haven't done so already.
At the moment what some people see as 'generosity' is just a sale by another name.