He also claimed there is a lack of understanding and education on the part of residents when it comes to having a factor.
The comments were made when factoring bosses gave evidence to MSPs on the Scottish Parliament Justice Committee, who were asking if it was too difficult for homeowners to change factors.
In defending factors the boss of Glasgow-based firm Hacking and Paterson criticised the level of understanding of some owners who queried bills.
The Evening Times previously ran a successful campaign highlighting the practices of some rogue factors and found cases of exorbitant charges, including a bill of almost £50 to change a bulb.
Following the campaign, Maryhill and Springburn MSP Patricia Ferguson's Factors Bill was passed by the Scottish Parliament, but there remains a separate law which means a two thirds majority of residents is required to have a factor removed and replaced.
Graeme Pearson MSP asked about the cases of £50 to change a light bulb, and wondered if there was a lack of clarity in bills.
David Doran, director of Hacking and Paterson Management Services, said: "There is a lot of unhappy people, a substantial minority. Many are unhappy because they don't understand the cost of changing a light bulb.
"If they don't do it themselves then it costs to get a qualified person to do it."
Last year the Evening Times reported how a couple from Baillieston were charged £48.44 by one factor, Peverel Scotland, to change a bulb in the stairwell of their block.
Their invoice stated £35 for labour and the rest for the cost of the bulb.
Mr Doran was also asked if he could see a way for owners to get justice in disputes with factors and satisfaction with their service.
He said: "There is a lack of understanding and education of homeowners of what they are buying into.
"There is the image of the factor that everything that comes from them is a lie, that is the major pattern.
"We get details of outgoings from Citizens Advice of people with satellite TV and mobile phone packages," but, he said, they can't pay their factors' bill.
Sandra White, SNP MSP for Glasgow Kelvin, is a member of the Justice Committee.
She said: "There was a certain arrogance on display that we see from some factors.
"They think they can charge what they like, and then when people complain, you get a reply from someone like Mr Doran who says 'you don't understand'.
"It was breathtaking arrogance on his part. How can they expect better relations with customers when that is how they respond."
stewart.paterson@eveningtimes.co.uk
