When not being able to reach an external number calling from the Kwebbl platform, first of all please check the accessibility of the To number from a couple of other providers.
In case the To number still cannot be reached - the problem lies in the To number itself. Here we cannot be of assistance, only the host provider of the number is to be contacted.
In case the problem only occurs from Kwebbl, please, raise a ticket with example call details (date and time, from and to numbers, detailed description of the outcome, error message observed/heard if any) and we will investigate the case.