To reiterate a point that has been made before, RA is an online storefront that has no inkling what each order looks like, or how it was shipped.
There are no RA "warehouses," only vendors (which can be large or small) who get sent the order for fulfillment, and then drop ship them.
The risk in ordering from RA is in not knowing who the actual vendor is going to be, and what/how they will ship. Results can be good, or bad, depending on the supplier.
Whatever the result, your contractual relationship is with RA, so contact them to have them make it right.
If this is the fourth bad order, then do a reverse search on the return address (they don't fake it, like Amazon does), and determine whether they all come from the same bad supplier, or more than one, as a matter coincidence.
In any case, provide feedback to them, so they can become aware (which they should catch internally anyway). If they don't respond satisfactorily, or take that into account, then it's time for an alternative.