Help, Very slow speeds!

I've been experiencing horrible speeds since the day my 7 day free unlimited offer was over, at best whtever is done only makes sure the line works at 1-2mbps with stupidly high upload speeds between 16mbps - 26mbps, This is so out of sync it's just scary. Every single experience I've had with support has been aggressive and dismissive. Hardly help is actually offered. Not everything can be fixed by restarting a router. Something I've done hundreds of times in various ways. Restoring defaults has little to no effect.