If they are transferring stock from Northern Ireland to Wolverhampton, then surely there is a chance that you are ordering stuff when it is in transit between the 2 places. I assume they would do all the stock of a particular item due to how it is stored in the warehouse.
Therefore, it can’t be delivered at it’s normal high speed as it needs to arrive at Wolverhampton, be unloaded, checked in, shelved and only then can your order be picked?
Meanwhile, other people are ordering items (or some of the items in your order) are still warehoused in Northern Ireland or already moved to Wolverhampton and therefore not being delivered.
Just me having a crazy idea to stop you all getting so upset 😀