Hayes got the letter after finding a nasty note on her car when she parked in a space reserved for veterans at a Harris Teeter in Concord, North Carolina.
"This parking is for veterans, lady," the note said. "Learn to read and have some respect."
Hayes posted a photo of the message on her Facebook account.
"I know I parked in one of the veteran parking spaces today," Hayes wrote. "I’m sorry that you can’t see my eight years of service in the United Sates Navy. I’m sorry that your narrow, misogynistic world view can’t conceive of the fact that there are female veterans."
Hayes also received an apology from the grocery store chain and the United Service Organizations.
The USO presented her with coins of accomplishment and the store gave her gift cards, which she donated.
"I'd like to give back to my veteran community, and (I'm) doing that by giving this back to veterans in need," Hayes said.
Hayes said she was initially frustrated by the incident, but now she's encouraged by all the positive responses.
"I think we like to say, 'It's 2016, there's no racism or sexism,' but it shows don't judge people before we take the extra time to think," she said.
"If you see someone in a vets' lot or handicapped lot, don't assume they are not, because so many of our veterans have invisible wounds of war," said John Falkenbury of USO North Carolina.