With the caveat that I know nothing about mailgun, so may have misunderstood parts of the conversation, it sounds, to me, like the salesman did a few very helpful things... 1. Pointed out that the user had been spending money on a service which was not actually being provided. Presumably, mailgun would correct this error. 2. Exposed that the "mail success rate" which the user was seeing might not be the full story. 3. Showed the user that he was paying for suppressed emails, so could (presumably) save some coin by cleaning up his list. (Note that the cost of cleaning might be higher than the extra payments, but good to know that there's a cost to suppressed emails so that the user can make a judgement.)

This rep was honest ("it was a template"), gave a specific agenda when asked, and gave useful information. Complaining that your rep has access to your data when that's his entire job is ridiculous. Data security best practices are that data should be provided on a "need to know" basis. In order to provide the above 3 values, the rep needs access to that data.

The other possibility, which would explain the different delivery numbers and different understanding of the dedicated IP status, is that the sales rep was confused, screwed up, and was looking at some other customer's data while thinking it was Phabricator's.