Refund of the released amount

Hello there

I have made a payment of $12 and released it also but the payment has been done on the condition that the project gets approved then 50% more payment to be done but if rejected then 50% advance has to be refunded now the project get rejected so want a refund and the seller is also ready for a refund but we both are unable to understand how to do that. 

Please support that ASAP