Cody O'Day and his partner Mackenzie Skorepa said when they returned to their tent last Sunday evening they found it flipped over, with the poles broken, food missing, an air mattress popped and a note telling them to get out.
The couple said they are homeless because of other troubles in their lives and there are limited spaces offered at local homeless shelters.
"Cody had nowhere to go. I just got into a home myself ... the lack of resources in this town has cause serious hardship for us," said Mackenzie.
"My faith in humanity kind of got crushed that night .. We are good people. There is no need for that ... Nobody has the right to go and destroy the last little bit of what people own," she said.
Abbotsford Mayor Henry Braun apologized for the incident at news conference on Wednesday morning, saying the city was "extremely sorry."
Braun said the volunteer removed some camouflage from the tent but denied that the volunteer vandalized it. The mayor said the unnamed volunteer is still doing volunteer work with the city.
The incident comes as the city tries to improve its record dealing with its homeless population. In 2013 city workers dumped manure in a homeless tent camp to try to drive out the residents, leading to a lawsuit in B.C. Supreme Court by homeless advocates.