When you book you always get an email with the itinerary, PNR, including airports of departure and arrival and times. Not having a confirmation is near impossible. Or did you book via an online travel agent (OTA)? Also they sent such information. If there is a schedule change, a bad operating OTA may not sent you information on the change. That is why it is advisable to always check your itinerary with PNR and last name at the airline.

That the ticket now may be 5 times as expensive when you bought it can be quite normal - it is very short before the flight, and then they try to sell the last seats for the best prices they can. Lots of people probably look for last minute tickets to be home or with family before X-mas.