When you fixed money in an account, they tell you the term of the deposit and how much interest you will earn on that deposit. The contract also state what will happen if you need to withdraw that money earlier than the maturity date. If you withdraw the money early, there will be a penalty payment.
If you do not know the Ts and Cs of your investment, you can ask them for it. If your financial institution has not informed you about the Ts and Cs before making the investment or are holding your money at ransom against your will without giving you the option for an early withdrawal, it sounds like you have chosen a very dodgy financial institution.