he even had call for an interview a week after applying ,visa officer asked him couple of questions regarding his job and length of the visit
If your brother was interviewed and his passport was returned without a visa then he was refused a TRV.
As he had appointed a consultant as his representative, the refusal letter would have been sent to the MyCIC account created by the consultant. Your brother will not receive any correspondence directly from the visa office.
There was a recent NDVO case who got a passport submission request within hours of his in-person interview