The most common reason for such dramatic swelling is that after the injection you probably had a salty meal or drink. If you have had alot of salt even within 2-3 days prior to the filler this can give you alot of swelling. The next time I would suggest going with a low salt diet prior to the treatment. Taking an antihistamine if you do not have any allergies or contraindications to it. If the swelling does not begin to decrease after a few days contact your doctor.
If you are unhappy, reverse the filler with hyaluronidase. I suggest waiting at least 2 weeks. Best, Dr. Emer.