Oh dear. Contact the buyer by phone. Attempt to resolve the problem. See what you can work out with the buyer. Burning question is 'are they or not?'
Don't answer me 
Right now the approach is contact: don't let the buyer think you are ignoring them. Dazzle them with your great customer service. Offer a compromise, delay his taking action against you
I don't want to know BUT wtf have you not kept money aside for refunds? Have you a death wish: this is no way to operate business. 'Oh money's invested, I can't refund you'. tch.tch. Get in the habit of having a certain amount of funds to cover payments: paypal like that,trust me.
And probably no-one else answered 'cause they were amazed at the question. 
__________________ REAP WHAT YOU SOW. LIFE IS SO NOT FAIR. | 
