With all lip fillers, swelling is expected, but this degree of swelling is marked. I can't comment on the technique, Volbella should not cause this exaggerated response. This will settle, 2 days of prednisone 50 mg am will help settle the swelling, as will ice. Could be technique, could be your reaction to the filler, regardless, see a Board certified Specialist who has plenty of experience with this product, and you will be fine. All the best, Dr Davin Lim Laser and aesthetic dermatologist.
Swelling, redness, discomfort and bruising is common during the first few days following an injection treatment, however this appears quite severe. I suggest you see your injector. In the meantime, you can use cool, soft, flexible ice packs (or small packs of frozen peas) to keep the swelling down. Place the ice pack on the treated area(s) for 15-20 minutes at a time, 3 or 4 times per day. Do not keep it on for too long to minimize the risk of frostbite (since your lips may be numb you won't be able to feel the cold as much). Keep your head elevated.
Severe swelling after Volbella
Volbella is a hyaluronic acid filler for the lips available in Canada, and I have therefore not had experience with it, but it is similar to other hyaluronic acid fillers that I have worked with.
You are smart to ice it, but I really think you should see your doctor, who may consider injecting some hyaluronidase and/or perhaps giving you some prednisone. The swelling generally starts to come down very soon thereafter.