First of all, institutions are required to send you the tax forms by 31 Jan. That's send; not receive, so you might receive it the upcoming week, so there's still hope. They also could have sent it when your relationship ended; if that's the case, you might not get another one now.
If you have the last statement you could provide the information on your tax return, but I wouldn't estimate it.
Do they have an online logon portal that you might retrieve your account info from?
If not, I'd wait a week for it to arrive and then start calling. Good luck!
Ricksun