It is not much serious to sell tobacco and its other products to the customer, but selling alcohol is serious; as the hadith which deals with alcohol curses those who are involved in it and it includes those carry and offer alcohol. So, though you are offering the alcohol on behalf of the company you bear the blunt of the curse; therefore you should make efforts to get out of the situation. If you sell products other than alcohol as well to the customers, then your income may not be considered haram but it will not be considered purely halal. You should try to avoid offering alcohol, though you have to look for another job.
Allah knows Best!
Darul Uloom Deoband