[Canada]Got suspended untill further notice due to false accusations

Hey reddit, I need some advice from yall, as im stuck and do not know what to do. Thanks in advance. Im a 23 year old student, i work at a telecom call center in Montreal since the last 3 years. I was told by the director that i was suspended untill further notice because one of our costumers called in told them that i was accessing his account to find his girlfriend number and then said that I sent her harassaing sms. I know the costumer in real as i have met him once at a party with his gf in Nov 2016. He found out that day that I work for the same company he has his cell phone with.He says later that night his Gf got some inappropriate sms from a random number (not mine) and he beleives that its me because i work for his cell phone provider and belives that i accessed his account and took his gf number the same night and sent her sms. I have no interest in his gf and i never sent any msgs. He made a complaint to the company in Nov 2016 and after everything was resolved and the complaint was closed, I went in his account in Dec 2016 with my supervisor to check the status of the complaint. Fast forward to july 2017, he called the company again and made the same complaints against me once again. Now the parent company has started an investigation and im suspended utill further notice. I never sent any msgs to his gf, its a case of false accusation. Note : The company I work for is a third-party and the Main company has started an investigation and the suspension order is from the main company. Sorry if i made any mistakes, english is my third language. Thank you for reading, any advice would help.