repay someone by something
to recompense someone by doing something; to settle a debt with someone by doing something. I will repay you by cutting your lawn free for a year. How's that? Can I repay you by taking you to dinner?
repay someone for something
to remunerate someone for doing something. I refused to repay him for his excessive expenses. She was repaid for her kindness many times over.
repay someone with something
to remunerate someone with something. The farmer's wife repaid the plumbers with fresh eggs and cream. We were repaid with fresh eggs from the farm.