"There are a lot of people hurting," he said.
He felt choice was being taken away from people, as they couldn't afford to fuel up.
Shannon's post on a Facebook group urging the boycott had gained some support, with membership increasing in just two days by 100.
He planned to have five-day stints with each company and doing it in a cycle to ensure all companies were covered.
He had been asked why not do them all at once, but that wasn't possible as some towns only had one service station.
"People still have to go to work, but we still have to get the message across."
He said if people were not able to boycott one station in one week, that was fine.
"It's about making a point."
Shannon had considered going to Wellington to protest but was concerned after what had happened in February where things had got out of hand.
"I don't want my cause to be lost."
He said he didn't want his group to be labelled as troublemakers.
"That's not what we are. We want people to have equal rights. Be able to have a life. Take their family out."
Shannon said everyone had the right to put petrol in their car once a week and go out with their families to the park.
But he felt people were paying twice - once at the pump, and then again at the supermarket.
"It's killing people in town."
Visit the Facebook page, fight against fuel price increases: https://www.facebook.com/groups/323296529735423