DLI Botox - will this vertical band in my neck go away?

The platysmal bands can be treated with Botox - aka "Nefertiti Lift. Watch a video of Dr Yew explaining how it works:
Another useful video to watch is regarding the truth behind Asymmetry. Most experienced injectors do not chase symmetry. Watch this video to see why:

Botox is used to treat a variety of aesthetic concerns. The results of Botox are temporary, typically lasting 3 to 4 months, and will fade gradually. As the product effects wear off you will slowly return to the look you had prior to treatment.

Vertical bands in the neck are caused by the platysma muscle. Botulinum toxin can be injected into the platysma band to relax it. If the platysma has significant laxity, neurotoxin will not be able to correct it. The most common muscle in the lower lip that is injected with neurotoxin is the DAO, depressor anguli oris. This is done to help relax the muscle pull of the DAO which pulls downward on the corner of the lip.

If this neck band is related to your DLI Botox treatment, it should improve as your Botox wears off. The band possibly became more active to compensate for other facial muscles. If this band continues to bother you, you could have it injected with Botox as well.