Voluntary Action Camden issued development worker Gabriella Morelli with a final warning in 2006 and dismissed her without any notice. An employment tribunal found that the organisation had contravened its own procedures by failing to issue a first or second verbal warning or a first written warning.
The tribunal also found that the failings of which Morelli had been accused should not have been classed as issues of misconduct, so were not sackable offences.
Morelli, who defended herself, argued that she should be reinstated, but the charity successfully counter-claimed that her job no longer existed.
The north London CVS, which was represented by law firm Russell Cooke, is not contesting the tribunal's findings but will appeal against the amount awarded, which came to £16,426.07.
Morelli, who has been unemployed for a year and has not worked since she lost her job, said: "Even though they have ruined my career and I feel they have acted vindictively, I wanted my job back because I'm proud of the work I did there and still believe in the organisation.
"I felt I had no choice but to go to an industrial tribunal in order to clear my name because I can't get another job without a reference."
The tribunal ruled unanimously that Morelli was unfairly dismissed, but reduced her award from £29,295.40 because it found that the "conduct which led to the dismissal could be said to be culpable and blameworthy".
It further reduced her award because of a failure to attend appeal meetings or the disciplinary meeting that led to her dismissal. It also found that she had been "uncooperative and difficult to manage" after the initial complaints about her behaviour.
A spokeswoman for VAC said that it would be inappropriate for the organisation to comment at this time.