Answer
No . The director did not lie to you.
Work Step by Step
Let us take 2 statements p and q
p : the director hire us .
q : we have mathematics or computer science , got a grade B average or better and took accounting.
So , for p to be true q must be true i.e. p→q.
But this does not imply q→p i.e. director will hire us if we full fill the requirements . Hence he did not lie.