Fiber broadband - 0.2mb speeds

Hi

I've been a talktalk customer for a few weeks now and my broadband stated off great at 22 - 24mb broadband. Although it's got a lot worse over time.

It's at the point now when I get home from work the speed is unbearable! I run a speed test and on average I'm getting around 0.2mb download speeds. I restart the router and I'm back to 22mb again but it does not last long.

Is my router at fault here or is this the talktalk network? If it's talktalk can I cancel as I'm not getting the speeds I was advised before taking out the contract?

Really hope some can help or adviser as it's driving me a little nuts right now!

Thanks
Gary