Paper Plus Masterton owner Russell Carthew said his business had lost thousands in sales because of the cuts.
"On Thursday, I lost about $1500," he said.
"In November, we lost at least two or three thousand. One of our computers completely crashed in the cut and it cost me $500 to repair.
"It's just not good enough."
Lynn Simpson, owner of Black Sheep Jewellery, said her shop had experienced regular outages over the past five years.
She said the cuts had left her and her staff on tenterhooks.
"It's like we're in the third world. We shouldn't have to be thinking 'oh God, when's the next power cut going to be?'.
"Every time there's a tree on the lines we lose power, and it's always the same people that are hit. It's awful seeing the shops on the other side still working. It makes it an [unequal] playing field for retail in Masterton."
Mr Carthew said he had been speaking with his energy supplier, Meridian Energy, which has been unable to say why the east side keeps losing power.
On Thursday, Meridian advised him to call Powerco - who were, he said, less than helpful.
"The person on the phone said, 'why are you calling us?' They were more interested in who told me to ring them than actually helping us out.
"After a while, they said 'we don't know what happened or how long it's going to take to fix'. They weren't interested."
Marlon Tortoza, manager at Iberia Restaurant, said he had received a similarly vague response.
"Contact Energy passed me on to Powerco, and the lady on the phone told me to go on the website to see when the power might be back on," said Mr Tortoza. "Well, I would have if I had power."
He said his staff were forced to contact customers who had made bookings to warn them they might be eating in the dark.
At Paper Plus, Mr Carthew is frustrated with the lack of information he has received from both his supplier and Powerco.
He says he wants an explanation for the cause of the outages and an apology.
"Paper Plus spends $25,000 a year on power," he said.
"They have treated us with complete disdain. You ask a simple question, and they don't have the decency to front up.
"I don't think they will ever compensate us. But an apology would be nice."
Dean Stevenson, acting network operations manager at Powerco, said Thursday's power cut was caused by a fault on an underground cable.
"Temporary repairs were made [to the cable] and supply restored at 7.30pm," he said.
Mr Stevenson said only one side of Queen St was affected because it was "supplied by a different source to the other side of the road".
