That means they are cheating.

Since they put in the intended date far late than your actual date.

If they are hornest, they should send the letter to CIS as soon as they cut your pay, and put the intended date not so late than the actual one. Or else, it is not fair.

But it is not worth arguing with them or even sue them. Since you have to ask for their sponsor ship to get the GC. Or else you may choose to jump to another company if you get a chance.