wha can I do if the seller want to change the contract after a ye

[Wanona McLain]

i been I nA sign contract with a seller for a home we enter a rent to own Contrat over a year  at $700 a month with $200 going towards the pur base of the house . now she the,t me instead of cal me to tell me she can no longer put the $200 towards the house sh can only do $100 which its not in the  Contract to change ..What are my option on this it was a 15 years contract I fell she trying to back out not behind d In Payments