Unfair Disciplinary Action?

I currently work for a company which has issued me with a disciplinary letter for unprofessional and unacceptable behaviour due to an argument I had with a colleague on facebook. I never mentioned the company nor was I even remotely offensive, however the letter says this action will result in... show more I currently work for a company which has issued me with a disciplinary letter for unprofessional and unacceptable behaviour due to an argument I had with a colleague on facebook. I never mentioned the company nor was I even remotely offensive, however the letter says this action will result in dismissal.

Thanks

I do not see how the employer can do this, what is written on my facebook account is my own personal account so how can they class my private life as unprofessional?

Any idea's what I should do because I am very close to taking this to court.

Th
Update: This was done on my lunch break on my phone not on company equipment, I was not derrogatory or contraversial everything I said was true, also in my original status I mentioned no names the colleague simply jumped in and assumed it was about her.
10 answers 10