Wigan chairman Dave Whelan paid a record £3million compensation for the St Andrew's manager, but Birmingham suddenly refused to let Bruce leave until he handed back £225,000 in image rights paid in advance. That was eventually settled by a £100,000 compromise.
But Bruce said: "I was utterly disgusted. It leaves a bitter taste. After six years' service I felt I deserved better than that. Familiarity does breed a contempt.
"The £3m was supposed to be compensation. I didn't want to read my contract details in the papers. It's become a bit of a laughing stock and it left me in an embarrassing situation, but now it's closed."
Bruce, accused of disloyalty early in his managerial career, was prevented from discussing the Bolton job when Sammy Lee was fired and earlier missed out on the chance to manage home-town club Newcastle.
He said: "They didn't give Bolton permission. Newcastle came in two-and-a-half years ago. But I'd just signed a new deal and signed four or five players, so I felt my loyalty was towards Birmingham."
Bruce finds Whelan's £3m outlay on him sobering. He said: "I think I only cost £1.25m in total as a player. I hope I can do the guy justice."