@zsergii are texting and data services working?
Are both accounts saying Active in their self serve accounts or when calling 611?
Try manually select the 3G / WCDMA ONLY network in your Mobile Connections area in your settings (temporarily) to see if this improves calling in/out for the time being.
Also you could try toggling into/out of airplane mode to help reset the network.
Hopefully if the network is having an issue, this will clear up soon.