[specialist]

Did prev company then compare with performance claimed by google, facebook, etc?

[makestuff]

I work in adtech and yeah if there is a discrepancy the advertiser will 100% contact their account manager about it. Same goes for the supply side, publishers maintain what they expect to be paid and will raise any discrepancies as well.

[riku_iki]

and does account manager help sometimes, or just retrieve standard template response?

[makestuff]

Usually it is just a misunderstanding of the metrics, but if there is an issue they will always open a ticket with the engineering teams. They also expect some level of discrepancy since the volume of data is so large.