Payment on behalf of customer

We are doing Yarn Sales Commission agency business. We are getting orders from customer and collecting payment from them and give to supplier. If any disputes in quality and quantity. The customer did not paid the balance amount. As per agreement we are the responsible to pay that balance amount. Example: Yarn supplied Rs.1 lacs. Yarn buyer paid Rs.90,000/- Balance Rs.10,000/- not paid due to quality problem. We paid Rs.10,000/- to yarn supplier on behalf of yarn buyer. My question is What is the necessary entry to pass this payment in our books of accounts?