Apalling customer suppotr

The customer service has been appalling regarding resolving an issue we have had trouble shooting renewal emails going out to members in the incorrect frequency despite the website saying it would go out at 21 days notice it was going out to members who had been expired for years or months. The other issue memberships were not overriding i.e. when a member was a student membership but renewed with a full membership it keeps sending the reminder to them they are expiring student membership. When this was raised with customer service/tech support, the person, named 'Sebastian' did not resolve the issue, ignored our queries, and would focus on writing rude emails regarding something else. Instead of helping to fix the problem, but said it was our problem to resolve! The appropriate response from customer service/tech support would be to listen to the customer, find the issue(s), and then fix it for us while providing us information and training to prevent the issue from re-occurring. This situation is forcing us to change providers. As a Not for Profit with no tech employees, we require NationBuilder to provide appropriate customer service. This should be expected of any provider.