If the phone you are using to dial is a 3G device or basic phone, dial *228 option 1 and let the phone restart - it will re-establish the network connection and update the roaming list/tower list and may fix the issue.

IF the phones(s) is a 4G LTE device, remove the SIM card, then reinsert and restart the phone - this is the equivalent of the steps above but *228 does not work on 4G LTE devices - you need to remove and reinsert the SIM card to reset the network.

Are you in an extended network area when yo try to make the calls?  Roaming?  How strong is the signal you are receiving?

PS--*228 won't work if you are in an extended network or roaming mode - you need to find a place where yo are getting a good signal for *228 to work.