A cough and cold lasting 7 days with no relief from cinarest and cough syrup, at your age, usually means the infection needs a proper check-up rather than more over-the-counter medicine. It could be a viral infection taking its usual course, or it could be an early chest infection, which needs a doctor to examine your chest and oxygen levels directly.
Next Steps
Please see a general physician in the next day or two for a chest examination; blood tests or a chest X-ray may be needed if the cough hasn't started improving. Keep drinking warm fluids and rest in the meantime.
Health Tips
Go to the hospital the same day if there is breathlessness, high fever, confusion or you stop eating or drinking, since these need urgent attention at your age.