从未:have never done/never did . e.g.我从未爱过你(I've never loved you.)
About 从来,there are two cases. A. When 从来 is followed by negative words like 没or不,it means the same as 从未 does, e.g 我从来没/都没爱过你(I've never loved you);我从不说谎=我从未说谎(I've never lied)
B. When 从来 is not followed by negative words, it means that you always do something. e.g. I always do my shopping in this supermarket. (我从来都在这家超市买东西). you can also put it in this way: I never did my shopping in other supermarkets besides this one. (我从未在其它超市买过东西。)
HOPE that i made myself clear.