Haley Tansey is claiming sexual harrasment and constructive dismissal against HBOS for incidents dating back more than ten years.
The worst, she alleges, happened on a business trip to Cheltenham in 1998, when she woke to find a male colleague, who cannot be named, in her room.
He claims he was invited and Miss Tansey answered the door in her underwear.
Damian McCarthy for HBOS said: "This is not a claimant who is a cowering wallflower, this is a woman who was assertive in the workplace, this is not an individual who was frightened or scared of reporting.
"It's the claimant who didn't actually believe these were acts of sexual harassment at the time."
He said her claims, which include another male collegue trying to lick her breasts on a work night out at Barracuda Bar, Halifax, were "exagerated, embellished and untruthful".
He added that she had been inconsistent in her evidence.
Miss Tansey claims she was subjected to sexual remarks and advances from a number of collegues and said she had to endure a "laddish" culture at the firm.
Ceri Widdet for Tansey said complaints had been made and slammed the company for failing to protect her. She pointed to "the total lack of a proper investigation".
"She did complain to numerous managers. None of the managers followed the guidance set out in their own policies.
"Nobody appreciated how serious the complaints were and there was a wholehearted failure to appreciate just how difficult it can be, especially as a female, to make a complaint of sexual harassment because of the impact it might have on their future career.
She said a female manager conducting a grievance hearing and appeal "adopted the sterotypical approach the complainant was responsible for the harassment".
She rejected HBOS allegations Haley Tansey had embellished her claims for £604,000. She said: "To sustain that level of lying, dishonesty and manipulation for financial gain over more than ten years is inconceivable."
The tribunal has retired to consider its verdict.