I tend to agree with your seller. I am down here in Florida and I was looking for drones coming out of my hives this afternoon. I did not see even one. If you have a nice day, do an inspection of the capped brood. if all you see are bullets you probably lost your queen. If there are no brood cells, that may be a good indication. Even better would be a small area of capped worker brood, flat brown caps. If you cannot find the queen and all you have is bullet tops, I would shake out the hive and let them move into your other hives if you have any other hives. Seems strange that you would lose 2 queens. Have you been feeding your bees. If so they may have been robbed and the raiders killed the queens.
If there no queens available to replace these and they are your only hives, you may want to freeze the frames to kill all of the bugs and save them for next year. This would give a package of bees a really good head start.