I recently accepted an offer for a management position with company A, and am set to start in just over 2 weeks. Today, I received an offer from company B, with whom I interviewed around the same time as with A.
Here is my issue: both the offer and the position with B are far more attractive than with A, but I've already accepted the spot with A. I have not signed a contract, but I have given my verbal commitment to join. Is it appropriate to now accept B's offer and call A to let them know that I am now retracting my acceptance of their offer? If so, what should I say to A?