I've located your account and I can see an issue with the network in your area affecting speeds at peak times - Ref.(F004833102). Our technicians are working to get this sorted and have set a review date of 12th April.
I'm really sorry for any inconvenience this may cause. I've sent you a private message (purple envelope at the top right of your screen) so I can grab some details and discuss this further.
Tech fan? Have you read our Digital life blog yet? Check it out