are you sure you’re calling it during the night?
if you are and it still doesn’t work, then the next thing that comes to my mind is that you remember the wrong layout, so i’ll show it to you:
1 2 3
4 5 6
7 8 9
* 0 #
and you need to call 999281#0 or 99281#0 (I’m not sure which one)
If that doesn’t work, the last thing i can think of is that you’re entering the numbers on your keyboard, when you’re supposed to chose them by the arrow keys and confirming with enter