The Number You have Dialed is not In Service.. when some one dial my PSTN number connected to asterisk

Hello everyone .

i have 6 PSTN numbers, connected to analog Digium card with 8 FXO ports (1A8B03F ), then it connected to an IVR, that pass the selected number to number of queues…

Suddenly when someone call my PSTN number(s), it give him recorded msg that the number doesn’t exist, it work normally when i restart asterisk…

your help is highly apprecaited

UPDATE: it fixed, it was my mistake, i configured the IVR with no time out so if caller did not choose a number he can hold the line forever