http://newsroom.sprint.com/presskits/sprint-spark.htm
Straight from Sprint
How Sprint Spark Works
Sprint Spark combines 4G FDD-LTE at 800 Megahertz (MHz) and 1.9 Gigahertz (GHz) and TDD-LTE at 2.5GHz spectrum. Sprint Spark’s spectrum assets, technology and architecture are designed to deliver a seamless customer experience via tri-band wireless devices. Tri-band devices, named for their ability to accommodate multiple spectrum bands, support active hand-off mode between 800MHz, 1.9GHz and 2.5GHz, providing data session continuity as the device moves between spectrum bands.
By this definition, customer infers that a spark city is using the three different bands as it says it combines the three different bands. so it is false advertising indeed