Buenos dias! Not being familiar with your brand since I live in the U.S., I do find that most brands have a lot in common. One of the things most share is the device that shuttles cold air from the freezer side to the fridge side. In most units, there is only one compressor unit and that feeds only the freezer side. A fan moves the cold air to the fridge side through a device known here as an air diffuser (sometimes called a dampner). This is small, thermostatically controlled door or louvers that opens and closes to allow more or less cold air into the fridge side. Either the thermostat or the motor that drives the device can fail. Both are easily replaced, but you need to first determine if it has failed. Simply move the thermostat to a colder selection number and observe if the device opens or closes. (You may have to hold the interior light shut-off switch mounted in the door closed manually). If you can't tell (sometimes they're hard to see), you're repairman can easily test the circuitry... Lo mejor de la suerte!...