Slow internet speed and drops

[Danb5]

For 3 years I was on Now TV broadband, 73Mbps was normal, swapped to sky a year ago, 73Mbps, now for I don't know how long it has been 50 Mbps, Tested with nothing using internet multiple times, on pc, on phone, on ipad, same slow 50Mbps, Guaranteed 60+ apparently yet I am only getting at max 54 Mbps, what do I do?

[Chrisee]

@Danb5 this page explains how the speed guarantee works https://www.sky.com/help/articles/sky-broadband-speed-guarantee