What are my options if the developer is delaying the handover of property?

I purchased a property from a developer and paid approx. 16% towards the purchase price.

To initiate the evaluation process, the bank demanded OUQUD from the developer and this cannot be produced because the subjected unit is already mortgaged with the bank.

This information was not revealed by the developer to me and SPA was issued in my name.

Now, they are delaying the handover of the unit because the unit has not been released from the bank.

What legal options are available to me and where should I file a complaint against the developer?