Refraction happens, yes. We can call it bendy light if that makes everyone feel better. "Bendy light" cannot explain sunsets, as the "bendy light" index isn't high enough in the atmosphere to bend light that far as to make it come from relatively above you to appearing below you. Even water doesn't have enough "bendy light" index to do this and it is much much higher than air.
How "bendy light" works is that light traveling through a medium is traveling slower than not, therefore it appears to follow a different path. It still travels in a straight line except it changes this direction at the termination between mediums. For it to make sunsets happen, it would have to deflect the light path in such a way as it was traveling away from you to the edge of the Earth, then reverse its direction on the edge of the Earth again towards you, so that you see the sun appear to sink below the horizon. Nothing has a "bendy light" index this intense. Once you get this high, you now aren't bending light, you are reflecting it.