Why doesn't my iphone 5s not have 4g?

I recently got an iphone 5s with Verizon. I have LTE but not 4G. It's always switching to 3G! So frustrating? Does anyone know how to fix it?

It depends on signal to the tower.

LTE is 4G for the record.
As far as why it is switching to 3G you may be in an area of weak LTE/4G coverage so it switches to the next best available option.