Last time it was complaints about PayPoint. Now it's Payzone's turn. Three retailers have been in touch to complain that the company has now set a minimum level of 50 transactions per terminal, charging them £2.50 a week if they don't hit the mark.

Jayesh Patel of Classic News, Northampton, was particularly scathing, writing to Payzone: "I would like to thank you for giving me three whole days' notice for the change of terms and conditions. This was very generous of you."

Sue Wilkins in Northwich, Cheshire, reckons she'll be left with about £10 a month commission. Both wondered whether they could put up a notice telling customers they would be adding a surcharge.

A third retailer, Chris Andrews in Cardiff, says she will now be losing money and was considering splitting up her transactions (for example, 2 x £5 instead of £10 in one go) to increase both her commission and her transaction levels.

Although all of the above is possible you may get customers complaining about surcharges, or queues if you split the transaction. But Payzone, as one would expect, takes a dim view. The company sent me its official reply: "Payzone is one of the leading consumer payments and cash distribution networks in Europe with more than 30,000 retailers in UK and, accordingly, there are some underperforming terminals. While we never wish to remove our services from communities, if terminals are consistently underperforming, we do have to seek to recover some of our costs.

"We expect less than 5% of our retail network to be affected by the new charge and, as per our letter, we will not charge if low transactions are a one-off, but will judge performance over a number of weeks."