verbal agreement

[tomac]

i bought a property at a knock down price for �90k and the contract stated �90k but the vendor was asking �180k for it but because of the condition i offered them The �90k upfront and agreed to pay them somemore money after i had lived in it for a year and added up the amount it has cost me to put it right, now they are saying that this was not the agreement and that they want all of the extra money, have we a verbal contract ?