Current response time from staff on here is around a week. Its a community forum with staff picking up bits as needed, not technical help. So its pretty unsurprising no ones replied if you created a thread yesterday (which BTW I cant see)
Whats a speed-test saying? Can you do one wired to the HUB from a PC?
How are you using Amazon? On a tablet? FireTV stick? Fire TV box?
Wireless is easily disrupted by a number of external factors, so a wired test is the best way to pinpoint if the issue is with the wireless or your line.
Have you got a PC or Mac that you could connect to the VM hub with an Ethernet cable and test speeds at http://www.speedtest.net/ to see if the issue is unique to the Amazon TV device.
Have you tried different services to see if the issue is specific to one service e.g. You Tube, BBC iPlayer, All 4, ITV Hub.
If you go to http://192.168.100.1/ to get the VM hub GUI. Don't login but instead click on Router Status which is either a button in the top right of the screen or a text link at the bottom of the screen depending on which hub you have. Click on the Downstream, Upstream and Network Log sections and copy & paste the figures from those screens and post them here, don't worry about the formatting or you can post screenshots if that is easier. Be careful to edit out or obscure any reference to your WAN IP in the log to protect your privacy.
The community can have a look for you and see if anything in the figures looks wrong and advise accordingly. Or you can wait for the VM staff to pick up this thread (can take up to a week) and run checks on your line.
Disclaimer - I don't work for Virgin Media. I'm just another VM user trying to help out so my answers may be wrong If my answer solves your problem please mark it as helpful as it may help others My setup: Vivid 200 Optical fibre with Superhub 2 in modem mode connected to a Netgear R7000 router. Telewest/VM user since 2001.