I would quote their own website to them

"If LESS than 25% of your order does not meet our health requirements, we will ship the remaining items that do on the scheduled ship date, and refund those that do not. If MORE than 25% of your order does not meet our health requirements, we will hold your order until the next shipping day. You will be notified via email."

It says that it will issue a refund--not store credit. Other places it states that either a refund or store credit will be given for DOA's.