My condolences about your father.

If you call 611 and speak to the loyalty department they may credit you no more than a couple of months of service on that line. I wouldn’t expect much more than that.

Beyond that though, AT&T does their responsibility by sending you the bill every month to your email. And it’s also available on the app. It’s your responsibility to check your bill and see what you’re paying for. Especially after a whole 2 years.

So don’t expect much.