Wrongful use of bank account

Hi,

I worked in Dubai for 3- 4 months during 2013 but left the job and left for India.

My bank account was open at that time and one of my colleagues started to use my credit card after I left Dubai without my knowledge.

He added his account to the beneficiary and done some transactions. I used to get some emails from this bank and thought these were some spam or marketing emails and did not give much attention.

But recently, I checked one of the mail and found that my credit is being used, having outstanding amount around AED 12,000. I then checked my old emails and found that these are done by the colleague in that company.

I don't know what should I do. This is a clear forgery act done by this guy in my name. I need take some action for this. Please advise.

Thanks and regards.