Face of Nation : Transport campaigner David Redgewell described Bristol Temple Meads as the “Poundland of national rail stations”.
The firm said it was fed up of people using its name to describe something “which may or may not be a shambles”.
A multi-million-pound project will see a new entrance added to the 179-year-old station and the roof refurbished.
Mr Redgewell, of passenger group South West Transport Network, was speaking at a West of England Combined Authority meeting to discuss the proposals.
He said the revamp was desperately needed as it was “the worst station” despite being the “gateway to the South West of England”.
In an open letter to Mr Redgewell on Twitter, Poundland said it was “somewhat irritated” by his description, and said its stores “never once closed due to overcrowding” and “have never failed to open because of the wrong kind of rain”.
It urged Mr Redgewell to think of an adjective that “more properly describes the shambolic state of the rail network and leave us out of it”.
Network Rail also took issue with Mr Redgewell’s description and described the Grade II listed station as “the jewel in the crown of Brunel’s railway”.
The rail operator is investing £40m over the next five years to refurbish the roof.
A further £26.6m is being provided by Weca to build a new eastern entrance to the station and into the Temple Quarter enterprise zone.
The refurbishment of the station is part of major regeneration plans for the area.
A former Royal Mail sorting office near the station was recently demolished to make way for a £300m campus for the University of Bristol.
