The seller is allowed to end all bids and then end an auction at any time. It is foolish for him to do so, since he pays fees based on the highest cancelled bid when he does this, even though he does not make the sale.
Or you may be misunderstanding what is happening. Many sellers have multiples, even of used items, often purchased as lots from liquidators.
Give a couple of listing numbers (not the sellers' IDs, that's not allowed) and we can perhaps see what the problem is.
