Translation Results Requested Through Conyac Made Public

I want to ask you about the folowing matter.
Package deal seems very popular in the buyer's country, but it is not in Japan.
The one product is sold as one product in Japan.
But as the buyer purchased the items and I don't want to cause trouble for ebay, I'll handle this problem.
Of course, I did not intend to sell one item as if it was two items.
Actually, there have been no complain by the buyers in the past.
In this case, how should I handle this problem?
Though I considered about it, I could not find any good answer.
Thank you for your support in advance.