Hello Sukhpreet,
I am with Sonali.
Pl mention the details of the situation--more the better, since this will give clarity of the situation to the members.
Coming to the bare facts of the case, given that your husband seems quite efficient, may be a better option is to change the job rather than getting into the situation that seems to be emerging in Airtel? Does he have that kind of time to spend on the course of action you suggest? The issue NEED NOT NECESSARILY be a right/wrong one--but more of prioritizing.
Sometimes it takes for an efficient officer to leave before the employer realizes his/her true value [have seen this situation even in very large corporations]. And since your husband worked here for 7 yrs, his performance would surely have been noticed by other top officials, apart form his immediate boss.
Rgds,
TS