Carrie is behind on her rent for her caf. She approaches her landlord John to see if the rent can be reduced. John says I

Carrie is behind on her rent for her café. She approaches her landlord John to see if the rent can be reduced. John says “I would hate to see the café close down Carrie why don’t I reduce the rent you are meant to pay by 50% for the next 6 months. So instead of having to pay $5000 a month you now only have to pay me $2500. 6 months later John and Carrie have an argument. John now says she has to pay him the FULL rent for the 6 months.

Will Carrie have to pay?