Oven temperature vs time adjustments
If you used a reputable recipe, followed it without variation, including using the same size pan as was specified, and adjusted for altitude, if appropriate, then:

The problem was likely with the thermostat calibration on your oven. The best thing to do is get an oven thermometer and use it to find out how much you need to adjust your temperature control. This answer to a question similar to yours may help with that.

If you can't do that right now - adjusting the temperature up in small increments (10-25 degrees F) and noting what happens, until you get the desired results, is a good plan. Remember that there will always be variables that can affect the cooking time and that most times given are approximate.