Prepaid rent now foreclosure sale

[Rachel Cooper]

I have been living in a property for 3 years. When I had a baby last year my dad paid my rent for me through January lease ends in March of 2017. House was sold at trustee sale. New owner says lease isn't valid which I know to be false. My lease shows I paid rent in full til January so am I required to pay him rent and or move??? He is offering cash for keys but it doesn't cover the money spent on rent through January.