Nennen is 'to call' so why the translation is 'to tell'?
The manufacturer's name was rejected!
I think that should be accepted. Please report it next time you come across.
the manufacturer's name = the name of the manufacturer ? Why not?
I reported it
Why "den NameN", not just "den Name"?
There's a bunch of nouns (called "weak nouns" or "n-declension nouns") that always add "-n" except in the nominative singular. Most masculine nouns ending in "-e" are like this, along with some others.
Reference: Weak nouns
Would 'nennen' be used in this context rather than 'erzahlen'?
Definitely yes (it's "erzählen" btw.).
"He will name the manufacturer for us" was rejected.