Report it up the chain. This is a map based on ISP-reported data. If there data is bad, the FCC can investigate. But the FCC isn't going to prove the reported data.
Let that sink in.
I did the pre-paid centurylink deal for one month, paid all fees up front, and returned everything to them on day 29. Centurylink .5 mbit DSL is absolutely useless.
The AT&T 4G LTE I averaged 30mbit symetrical, maybe a 3/4 of one United States imperial mile to my nearest tower.
After filing the complaint, I had them trenching my back yard in two weeks running 360 feet (sorry I can't metric) of coax.