He said he sometimes used his own money at the booth over the years when a motorist came up short of the owed amount.
"In my eyes there was no crime committed, I just helped somebody out," Samsonov told WBBH-TV.
Samsonov said bosses had previously asked him not to help customers pay their tolls, but he had never been formally disciplined.
The Gasparilla Island Bridge Authority told Samsonov his work week would be reduced from five days to two days as punishment, and he was terminated when he refused, Samsonov said.
"If I can't be trusted for five days, how can I be trusted for two days?" Samsonov said.
The bridge authority said it does not comment on personnel matters.
Samsonov's daughter, Patricia Samsonov Gillis, thanked supporters on Facebook.
"Please know that this is Sam's second retirement after also having been in the military for 26 years and he is well taken care of with benefits. As we spoke yesterday, he stated he would reach out to the local hospital to become a volunteer a few days a week to keep him busy," she wrote. "His only regret is no longer being able to interact with each of you and he wishes you all the best."