"This is what happens to customers who don't pay," Calum announces in the clip. "They get a refund, free of charge."
The clip has been viewed tens of thousands of times — and received almost universal praise for the hard-working brothers.
Waiting for your permission to load the Facebook Video.
"I can honestly say that since we started in business we have had nothing but good relations with our customer base," they wrote alongside the clip. "Unfortunately, today we came across our first real life knocker (a person who intentionally withholds Fair payment for the purpose of personal gain)."
They said that after hours of being lied to and being bounced back and forth, they came to the realization they'd been played, and that the customer never actually had any intention of paying.
"We spent 3 hours in the blistering heat tidying this person's home up for them only to be ripped off for our money and therefore we took the decision to give them their waste back," they wrote.
"Wrong, Right? I'm not looking for a debate, we are just making it clear that if you think ripping off working men for their wages when they have children to feed and homes to run then you will be getting a seriously big load of crap put back on your toes."
The brothers said they had even given the woman a discount, only charging £120 to clear the items, when the job would normally cost £200.
She told them she would be back with the cash, but never returned. They called her several times, but she ignored them and eventually blocked their numbers.
Right before she did, the brothers told her they would send her all her rubbish back if she didn't pay; she dared them to — so they did.
"It was pre mediated, they never did have any intention on paying, they completely ruined our day and forced us to cancel other jobs too," the brothers wrote on Facebook.