Where there is life there is always hope. But that is a hard one. Part of it depends on how valuable those eggs are to you.
I'd keep going for a few more days. Those chicken eggs can be pretty tough. They will develop some at fairly low temperatures, like in the 80's Fahrenheit. They won't hatch at these temperatures but if you store them on the 80's before you start incubating, they may develop enough that they will hatch quite a bit early. I don't know if what yours have been through was enough top kill them or just delay the hatch a bit.
It may be a day or two before you decide you have the problem solved. Why not keep going and candle them in a few days to see if they are still developing? You don't want to start another batch of eggs until you know you've solved the problem anyway. I don't see this as costing you anything.
I've read where the temperature being too high the first few days can cause deformities in the chicks. I have not read anything about the temperatures being too cool causing deformities.
Obviously what you've been through is not good. It may be fatal, I don't know. Once you have the problem solved the safest thing to do is to start over. But I'd probably keep going, partly just to see what happens.
