Thank you for your question and sorry for the late reply.
What tasks you have to do depends on the terms and conditions that you and your employer agreed on in your contract - it has to specify that. If it says that your only job is to cook and nothing else, then of course it's not legal for your employer to ask you to cook and clean at the same time. Unfortunately it could be that your employer used a very broad job description that also includes taking care of the kitchen etc.
You might need support by an organisation that is specialized in labour law. If you tell us where you are living, we can do some research about counselling centers that you can get in touch with.
For now I will link @Franziska_jobs4refugees and @DavidJ of Workeer. Maybe they can help you to find a solution to your problem or they know organisations that you can get in contact with. Or they can show you how to use their websites/programmes to find a better job than the one you are currently stuck with.