Hi @ab,
As of right now, there is a soft limit on the calling minutes for the Sales Pro subscription. This means that we can add more minutes to your account for no additional charge. You would just need to reach out to the support team to request more minutes be added to your account. However, we may implement charges for additional minutes in the future.
There is a hard limit of 15 minutes of calling per month for free users. We cannot add additional minutes; free users must upgrade to get more calling minutes.
-Caitlin