Possibly it's time for very strict put down, leave, put down, leave, put down, leave (in the style of Jo Frost) until they get the message.
You CAN ignore them!
However, it's nigh on impossible if the cots are in the same room - can you re-organise sleeping arrangements if that's the case?
So the other key message here is DH not helping enough. Since he can't breastfeed them he can: do the Xmas food shop, clean the house from top to bottom, do all the laundry, cook the meals for the next couple of days, send you out the house for the X hrs you would be able to go out the house between feeds (presumably around 4 hours of blissful free time just away from being needed).
You can't go on like this, you'll make yourself ill but in order to get out of this scenario you need to be firm with the twins at night, and extra firm with your DH by day - he needs to step up and be a supportive husband - their bfeeding is no excuse to say he can't help as there are numerous other things he can do.
If you're going to get the message through to him it's going to have to be very clear, black and white - he's clearly not figured out on his own that you are exhausted and that no one could go through what you're going through ongoing week after week and remain sane. Tell him to step up - do it preemptively before he comes back on Wednesday so he knows what he's doing from the moment he steps back in through the door.
That's all I got.