While you may not be a US citizen, the US Embassy in Chile offers a clear directive on what to do for those who overstay:
If you have stayed in Chile for more than the allowed time period, you will not be allowed to leave the country without paying a fine. This fine cannot be paid at the airport, so you should pay it before attempting to depart Chile. To pay the fine prior to your departure, you should go to the Departamento de Extranjería and make an autodenuncia or complaint against yourself in the Sanciones office. Upon doing this, you will be told how much the fine will be, and once you pay it, you can depart Chile.
If you attempt to depart Chile without paying the fine, your passport will be confiscated by the airport police, and they will give you directions on how to pay the fine. This process involves going to multiple Chilean government offices, first to find out how much the fine is, then to pay the fine, next to show that you have paid the fine, so that you can get a document indicating your passport should be returned, and lastly, to retrieve your passport. The entire process may take from several days to three weeks.
Should you need consular assistance to return to The Netherlands, here is the contact information:
Embassy of the Netherlands in Santiago
Chile Apoquindo 3500, 13th floor
Las Condes Santiago Chile
Telephone Number: (+56) 2 2756 9200
Fax Number: (+56) 2 2756 9226
Should you not be a Dutch citizen, you may need to contact the embassy or consulate that represents your nation.