We get calls like that also. But while his call could be from FB, the call that we received to me sounded suspiciously like a third party or possibly a company

We get calls like that also. But while his call could be from FB, the call that we received to me sounded suspiciously like a third party or possibly a company trying to get a leg in by making you think they are facebook when they are just a company offering to help you with FB advertising. This actually happens with some frequency with people trying to claim they are google when they are just trying to offer consulting around what google offers. (Next time it happens I will attempt to not hang up and dig a little deeper. But it is not unusual for third parties to make reference to a known company and throw their name around. Back in the day this was actually quite common with copier dealers claiming to be Xerox.)