Leslav was a peat digger from Downwarren and worked in Crookback Bog. In 1272, a monster was attacking and killing the workers and so he paid a scribe a dozen eggs to write up a notice for help in dealing with the creature.
If Geralt helps him but haggled: after Geralt killed the foglet and came to collect his reward, Leslav gave him a smaller amount. When Geralt called him out on it, the peat digger admitted he didn't have enough coin to pay the witcher.
If Geralt demands pay right then: scared, Leslav paid all he had on him, but it was only a portion of what was agreed on.
If Geralt agrees to wait a week: Geralt showed up a week later and Leslav was true to his word, returning the original amount plus interest.