Failing to serve a notice before the expiry of tenancy contract

Hi,

My flat contract will end on Jan.14.2020. I went to the office of real estate last December 3 and I was told I will pay for 3 months as a penalty since I have not complied with the 60 days' notice period.

I have been living in this flat for 3 years and they are not giving a discount and all other residential flats here in Al Barsha are going down except for my current building.

The difference is really big if we are talking about a 2 bedroom flat. I was advised to renew and extend for 3 months. But I really want to move out.

Please advise me.