Wallin gave an interview to the CBC on Thursday night to give her side of the story on questionable expense claims that have dogged her for months.
She says the prime minister's new chief of staff, Ray Novak, and the Tory Senate leadership told her she was not "representative of the views" they wanted to have in public and she had to go.
Wallin has kept a low public profile while awaiting the results of an independent audit into her expenses, but says she decided to give her side of the story because the audit has been delayed.
Wallin, who now sits as an Independent in the Senate, has paid back $38,000 in expenses and says she may have to repay more.
She blames the expense problems on failing to properly deal with the paperwork required to submit expenses.
"There's a lot of paperwork particularly in government, every time you move, every time you go anywhere. Sort of more paperwork than is humanly possible to keep on top of. So I made mistakes," she told CBC's the National.
An examination of Wallin's travel expenses from September 2010 to Nov. 30, 2012, showed she had claimed $29,423 in what's deemed regular travel to and from her home province of Saskatchewan, while racking up another $321,000 in other travel elsewhere in Canada and abroad.
Wallin said the questionable expenses concern business flights related to her membership on several corporate boards but were not for the Conservative party.
"I did very little direct party work," she told the CBC. "Obviously in Saskatchewan, I went and campaigned for some of my colleagues, obviously I would do that. But, there weren't charges associated with that, because I'm actually at home."
Wallin said she never talked to Prime Minister Stephen Harper about her expense woes but did keep his then chief-of-staff Nigel Wright in the loop.
She said Wright never offered to help repay any of her expense claims as he did with Sen. Mike Duffy.
Wright resigned last month and was replaced by Novak after a firestorm of negative publicity for ponying up $90,000 to bail out Duffy, who also is out of the Conservative Senate caucus.
Wallin said her expense woes are completely different from Duffy's and those of Senators Mac Harb and Patrick Brazeau, who have been told to repay money they claimed as a housing allowance.
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