Hi [NAME],   Unfortunately, if your customer has the wrong configurations from the order, you or the customer will need to contact the customer service for refund or arrange engineer to replace the necessary components after confirmation from the technical sales team review. 
Hi all I'm from Dell China. I have a customer bought R7515 config chassis with 24 nvme backplane.And R7515 also support for order with Gen4 nvme u.2 ssd. But when customer recived server,he find out that all the Front accessible nvme drives currently only support PCIe Gen3.Then customer argued why we support sell Gen4 ssd with R7525? Now if we have any advise for help to adjust Gen3 to Gen4?
R7515 24 nvme u.2 backplane problem