The reason its hard to get help through the call centres is because first line response is from some third world hell hole chosen for the availability of cheap but poorly qualified staff, rather than with a view to providing customer service. As VM already know this full well, and can themselves see and read the appalling customer feedback on sites like Trustpilot, they clearly don't care and we can be sure that this situation is not going to change any time soon. We (other customers with time on our hands and a sense of charity) will try and help you), and if you're lucky the VM forums staff (who are UK based) will look in to see if they can assist.
As with many things, getting it fixed is easier if you have a fair idea of what's wrong, so if you can do the following we can possibly assist. You're not gaming over wifi are you? That introduces a whole lot more variables and makes fault finding more difficult. Assuming you're not (or have access to PC with a wired connection to the hub), then do the following:
1) Post the Upstream and Downstream tabs of you're hub's router status pages here, and somebody will take a look for obvious problems.
2) Run an Ookla speedtest with the default VM servers, is that showing what you expect?
3) Get over the thinkbroadband.com and create an account, and set up a Broadband Quality Monitor (BQM), but making sure the titles is not your IP address. Let that run for a day or two and post a link to the snapshot chart here.
The reason its hard to get help through the call centres is because first line response is from some third world hell hole chosen for the availability of cheap but poorly qualified staff, rather than with a view to providing customer service.
I prefer the official line of "We have invested in providing UK centres of excellence, whilst our partner CSC's will pick up first line support"
See I just made that up. In my head. Which explains what VM's press release team do....
As a Very Insightful Person, I'm here to share my knowledge. I don't work for Virgin Media.