Onestream Overcharged Me For Slow Internet and Gave Wrong Contract Cancellation Dates

I regret choosing Onestream for my broadband service. Unless you pay extra, their basic router is quite simple; so, I had to get a stronger router for £50 to have consistent internet. Still, the internet speed has been regularly slow, much below what was promised. Worse, my monthly payment went from £28 to £37 from unannounced price increases without warning. Their messy customer service is most annoying; I have repeatedly called them to cancel my contract, yet I keep getting emails with erroneous termination dates. I get guaranteed the problem would be resolved every time I contact, but nothing changes. Onestream's service has been pricey, erratic, and shockingly impossible to control.