If the hotel does not match the description provided by the tour operator or if there are issues that you were not told about beforehand, you should talk to the hotel staff or your tour operator straight away. If you do not complain about any issues that you encounter while still at the hotel, you usually will not be able to invoke these later on.
If the tour operator or the hotel staff fail to rectify the problems, you should send a written complaint to the tour operator as soon as possible after your holiday and ask for a discount on the basis of defect. Germany’s package holiday laws stipulate that all complaints must be made in writing and within one month of the end of the holiday. Any claims made after this deadline will not be entertained. Many other countries have also chosen to impose a relatively short deadline for complaints, usually between one month and a couple of months.