If this would happen to you, please notify the Housing Service and Social Council. You have to read your contract very carefully. This contract is specific for the situation of students and protects them against dishonest practices of landlords. Make sure they don't add any supplements. In case you have to take exams again in August, you should be able to get the room for free for the exam period.
Some landlords also add house rules.
If you sign the contract, you are also obliged to the rules and most of these are very strict. Usually, the deposit is 3 times the monthly rent. Make sure the deposit is put in an account on your name. Do not use the deposit to pay the last month's rent. The sum will be returned to you when you return your keys and no damage is assessed.