Bhavin Patel stocks up at Costco's Chingford branch in Essex, although I get the impression it is not often a happy experience. He has been copying me in on emails he has been exchanging with management there for the past couple of months.

Here is a taster: "I am writing to inform you that I have been overcharged yet again as a result of my goods not being scanned correctly. I purchased four cases of beer among other goods this afternoon and spent a total of £3,140.77 at your warehouse.

"Instead of being charged for one case of Carlsberg Lager (500 ml) cans, I was charged for two cases of Fosters (500 ml) cans, when I only purchased one of each.

"Apart from this, your tobacco room staff miscounted the amount of tobacco outers I had purchased, which resulted in further delays. This latest overcharge is now the seventh in the past few months, and despite assurances from you, I regret that I see no improvement in service."

Bhavin, who is unfailingly polite in his correspondence, adds: "Through these very difficult times, I find it astonishing that a US company which states it prides itself on service and member feedback, can turn round and state to a member whose average spend per visit is £3,000, that if they don't like the service they offer, then feel free not to shop at Costco anymore!"

He wonders whether others have had similar experiences.