Custom dictates that the person whose name is written on the contract papers is the contract holder, and if that is the case then you are the contract holdr and you must fulfil the contract, because Allaah has enjoined fulfilment of contracts. He says (interpretation of the meaning):
“O you who believe! Fulfil (your) obligations”
So you have to pay off to this company with which you made a contract the money that becomes due as the result of this contract. It is not permissible for you to try to evade that.
Then if you allowed this person to benefit from it on the basis that he would pay the instalments, you can ask him for these instalments yourself.
And Allaah knows best.