Unfortunately, there can be problems with VoIP services in the Middle East. These problems are due to local governmental policies. This results in some Talk360 users not being able to make a connection in this region at this moment.
However, these blockings are not permanent and not applicable to all regions. There are also customers able to make successful calls.
Please see if the VoIP is blocked for your provider and try again after a couple of days, as you may be able to call again.