costa rica border crossing HELP with bought car

sorry for the quick write up but currently stuck at the border between panama and costa rica and not able to get our car through. we bought it yesterday from another travelling couple who had come through the day prior with it from costa rica. in costa rica your car is give 90 days as a foreign car to be there. the car is registered in california. all the paperwork and transfer title is correct but they will not let us through due to the cars previous permit that was used by the previous owners.