AN angry son confronted a salesman after he discovered his vulnerable mum had been sold two new doors for almost £6,000 - when all she needed was a £50 handle.

Dominic MacMahon claims double-glazing company Zenith Staybrite pressured his 81-year-old mum Dr Heather Collins into buying the new doors.

A salesman spent two-and-a-half hours with the widow at her Lexden home at the end of which Dr Collins handed over two cheques, worth £5,743.73, for new front and back doors.

But Mr MacMahon claims the doors were “not needed” and when he heard what had happened - from Dr Collins’ evening carer - the insurance broker returned the following day and filmed the salesman at work.

In Mr MacMahon’s video, which has been widely shared on social media, the salesman denies any wrongdoing and claims he was unaware Dr Collins is suffering from dementia-like symptoms.

Mr MacMahon, from Layer-de-la-Haye, then puts a string of questions to the rep, asking: “How would you feel about threatening old people like this?

“This is all she’s got - that is all her savings.”

When the salesman admits he stood to make about 10 per cent in commission from the sales, Mr MacMahon then adds: “You’re getting £600 for ruining my mother’s life. How do you feel about that?”

The company has confirmed Dr Collins’ order has been cancelled and an investigation has been launched.

Dad-of-two Mr MacMahon decided there was no other way to highlight the issue after reading a book by journalist Jon Ronson called So You’ve Been Publicly Shamed.

He added: “I needed to emphasise to people what this man had done.

“I was angry but by being able to put the footage online and tell other people what is going on makes more of a difference.

“This is one case - how many other people are going through this? Some people won’t have sons to fight their corners.

“As my mum was writing out that cheque for nearly £6,000, what was going through his head?

“It’s not sales - it’s preying on older people.

“Mum struggles with time and quantity - she has no idea what the implications of signing a cheque for £6,000 are. She actually thought she had bought two door handles for nearly £6,000.”

Dr Collins’ cheques have been blocked and the company will receive none of the money.

A company spokesman added: “[We] will, where and if appropriate, take robust action to ensure the business continues to adhere to industry-leading customer service practices.

“Zenith is committed to the highest level of sales and customer service practices. A strong customer service offering is key, and as such we take any complaint or incident very seriously.”