Last week we featured a story from a person who received a threatening solicitor’s letter from the ESB about his last month’s payment after he switched from the ESB to Bord Gáis Energy.

An ESB spokeswoman said that the letter was sent out “inadvertently” as a result of a glitch in the system and she denied that such an approach was common practice.

It turns out he was not the only one to get legal missives from the ESB, as our readers were quick to point out. A reader called Holly “was sent a similarly threatening letter demanding payment of €11.93 (for a bill which I never received)”. She says that “failure to comply within seven days would have led to a debt collector being sent to pick up the tab – and I only received the letter eight days after it was dated. I am ever so glad that ESB has finally let my account go to Bord Gáis, after three months of waiting for us to be switched over. To hell with them.”

John Murphy said he had “the exact same experience” and when he contacted the ESB “to ask why I was treated so shabbily”, he says that the representative just “continuously repeated the mantra that the direct debit had been cancelled. If anything were needed to demonstrate that the ESB does not understand the true nature of competitive markets it is this.”

The same thing happened to a reader called Anna, “which suggests this is not a one-time inadvertent mistake. This practice, while disrespectful, can also cause cash-flow problems for older people.

“My mother puts the same amount of money into the account every week to cover the bills – a method which in effect is a saving mechanism for winter but also allows her to budget effectively. Receiving the bill with the solicitor’s letter meant that she felt like she had to pay the bill straight away in one lump sum.”

Brendan Keenan had a similar experience when he switched to Airtricity. “Unusually, the solicitor’s letter had no phone number on it, nor was it listed in the phone book, nor directory enquiries. I had to ring the Law Society to get the number. I was informed by the solicitor that it was a mistake. I received an apology by phone the following day. How much did all that cost the ESB?”

How much indeed, and just how many of these solicitor’s letters have the ESB sent out? We contacted the company again and a spokesman said that solicitor’s letters had been sent to “a good number of customers”. He said that the ESB issued some 13m bills each year and such a high-volume business required a lot of automation. He said the normal process meant that if someone went into arrears, they were sent a number of reminders and were contacted by phone. He said a solicitor’s letter would only be sent at the very end of the process and pointed out that the ESB was widely recognised as having an understanding approach to people with financial difficulties who were struggling to pay bills.

The entrance of competitors into the domestic market had exposed a flaw in the ESB’s computerised system, which effectively meant that some people who switched with sums outstanding leapfrogged through several steps in the credit-management system. This automatically triggered the sending of a solicitor’s letter.

He was unable to say exactly how many people had been affected but said the automated letter had now been pulled from the system and people who had received the threatening correspondence in error would all receive written apologies.