We recommend that the supplier handles all customer service questions pertaining to their products, as the supplier controls their return/refund policies. If a retailer receives a request pertaining to a partner product, they should pass the request to the supplier's customer service team.
To streamline this process, we recommend that you provide your customer service team with a list of the products that are sold by partners on your store and the partner's contact info. This will assist them in directing customers when anyone calls or emails with a question. When replying to a customer service email, you can also CC the supplier's customer service team in the reply, and let the customer know that they'll handle the request from here.
For more information on returns/refunds, please refer to this article: