Indis bro, I think then i will have to consider myself as lucky, they knew everything before hiring me and i told them that they do not need to sponser me but once you are with the company for 5-6 months, you will know everything about that and also they dont want to fire you since you donot have work authorization, what you can do is talk with HR and about the sponcering you. Since i work as an accountant, i know whats going on so it makes my job easier. First you need to go inside and once you are inside the house, it will be lot more easier and also you have experiance also. Best of luck