He accuses Costcutter of "profiteering" and maintains that its "family members" deserve better treatment than this. He has been with the group for more than 12 years.
Among other things, he said: "They preach this family image and then rob their brothers. They are showing themselves to be nothing more than estate agents. Loyalty counts for nothing. They moan in magazines like yours about retailers' hard times and then take an extortionate sum for a direct debit."
He has asked to remain anonymous because he needs to have Costcutter above his door (to advertise his cheapness) and fears that if he identifies himself there will be further retribution.
I asked Costcutter to comment. A spokesperson replied: "Our retailer contracts state that there is a fixed charge for failed direct debit payments and retailers are advised and given seven days' notice before the charge is enforced, as well as given 14 days' credit. This charge has not risen for four years and is in place to cover the cost of recovering the outstanding balance and, importantly, to act as a deterrent against failing to meet payments.
"We would prefer not to have to charge for failed direct debits, and remind retailers to contact us directly to discuss individual circumstances and complaints which can then be dealt with accordingly."