Council tax rebel Sylvia Hardy has said she is prepared to go to jail again.
Sylvia Hardy was angered her prison protest was halted
The 73-year-old retired social worker from Exeter was jailed on Monday for refusing to pay an increase more than the rate of inflation on her tax bill.
But she was freed on Tuesday, less than two days into a seven-day jail term, after a mysterious donor paid the £53.71 council tax arrears on her home.
Ms Hardy said she was withholding money from this year's council tax bill and expected to face the courts again soon.
Ms Hardy, who argues the tax is unfair on retired people, had been due to be freed on Friday.
But her arrears were paid by a "Mr Brown", so prison officials were duty-bound to release her.
However, she said she was disappointed not to have served her full sentence at Eastwood Park Prison in Gloucestershire.
She said after returning to her flat: "I'm glad I'm home and back to a comfortable bed and decent food. But I'm disappointed, cross, angry, whatever, to have gone to all this trouble and then not be allowed to serve the full seven days."
Her stance was supported by pensioner groups.
Albert Venison, of the Devon Pensioners' Action Forum, said: "I think it's really wrong that someone paid the money.
"Sylvia made it a matter of principle that she was going to prison. She also made it quite clear that she didn't want the money paid on her behalf, but people simply ignored her wishes.
Sylvia Hardy said she had many messages of support
"The authorities should have said: 'We can't accept it because Sylvia told us that she did not want it accepted', and that would have been that."
Ms Hardy said her protests would continue.
She said: "I've already had the final demand for this year's council tax and no doubt I'll get notice in a couple of days saying I've been referred to the courts again.
"It's no good giving up now because, if we do, the powers-that-be would rub their hands saying: 'We knew if we made it more difficult for them that they'd give up in the end'.
"As long as we're still alive, even if it takes another few years, we'll carry on.
"I told the girls in prison that I might see them again."