Had a reservation but all self service machines out of order. One person serving on tills, one more dealing with customer service queries. Took more than 5 minutes to serve person at top of queue and at least the same again to deal with others ahead of me in queue. Did ask if more people could be put on checkout but apparently this was not possible. Employees very polite and apologised for delay but also got 'we can only work with the tools we have' platitude a couple of times. Was also advised that the self service machines were out of order at other stores - something to do with a 3 for 2 - surely if it's planned downtime/maintenance, stores could schedule more check out operators. Luckily I examined my four items before leaving as one was smashed to pieces, so then had to wait to be refunded - and to add insult to injury will need to wait several days before the refund wiil appear on my credit card. Overall not a great experience!