It is demanding that banks reform the Banking Code to force credit card issuers to allow a minimum time for cardholders to pay - and it wants that time to begin the day the bill is sent, not the day it is printed.
The card companies' underhand trick to make it difficult to avoid paying interest is revealed in this month's Which? magazine. It says some issuers admit leaving bills lying around for up to four days before posting them to customers.
That means some people are left with just nine days to pay their bill.
A cheque sent by first-class post would clear seven working days after arriving with the credit card company and that means, with a weekend intervening, that you have missed the deadline and the interest charges will kick in.
The Consumers' Association recommends you pay by direct debit to get round the problem.
But if you are stung because of having too little time to pay, you should demand a refund.