My bursary contract states that in instances where an offer of employment has been made I am required to render one year payback service for every year of study for which the bursary was awarded. I have been waiting for 5 months and have received no written communication that the bursar intends to employ me. They have told me on the phone to "sit tight and wait until the end of March" for them to contact me at all - there is no indication that they may even offer employment. How long do I need to wait for an offer of employment before I am no longer obligated to render payback services?