I just wonder how this is possible? Obviously it shouldn't happen, but how is it actually possible?

I ordered something last week, didn't realise it was a Private seller , not bothered about that, however, I was wondering where it had got to, and took a closer look at the listing.

Blind Drop Shipping is stated and it did state 3-5 days  free delivery and i was happy with that, but i hadn't remembered it was  Easter so the 5th day will actually be next Tuesday. 

How do the blind shippers get the SD label?  I don't think they can. The item is £11 and I tried listing it to see if i could get custom postage on it and I can't. Everything the seller sells is under £12, and my item would not fit a large letter. The seller is communicative (not in English though) and says my item has been sent, but Evri don't have it yet.

Does this mean that the seller must be charged for SD and get refunded for each SD label purchased. Don't they have to request refunds individually for each label? Or could the seller have a deal with the drop shipper to use the SD labels? I am intrigued.