PHONE KEEPS GETTING BLOCKED

My husbands business phone keeps getting blocked and nobody at Vodacom seems to be able to tell us why!! The lame excuse I received is that at 2 o'clock in the morning the system detects that the phone is out the country and automatically blocks the phone - this despite the fact that my husband has roaming!!! This is now the third time this has happened, I need somebody to provide answers please and rectify the problem!