Have you given the ewe Calciject? If you just let her go downhill then she will die. I don't know what Loxicom is so maybe that's the equivalent. How you are describing your ewe is simply not what you would ever expect of a Heb - they are, as I'm sure you know, the best mothers ever. If you can treat her and she gets up, then pen the family and leave them overnight - by morning you should find she's fed them.
Trying to get an unwilling lamb to feed is one of the most frustrating jobs I find.
To see if they're hungry, check their bellies and bump your hand on top of their noses. If their tums are not bulging and they push back upwards against your hand, then they do want to feed. Put a clean finger in their mouths and see if they have a sucking response.
I would leave them for 4 hours after a tubing before trying a bottle. If possible, can you sit the ewe on her bum and milk her into a bottle, using a lubricant. That will be better for the lambs than any formula.
Check that the hole you have cut in the end of the bottle teat is the right size - too small and feeding is too much effort, too big and they drown or choke.
Try squeezing a little milk from the bottle into their mouths, or rub it over their lips and give them the chance to lick it off, before getting the teat back in their mouths (I know, that's the time it all goes wrong and if you're like me you get filled with impotent fury. You just have to be patient and keep trying.