VM Router : New Address, New Router hub4

[copernob]

Hi All,
Virginmedia has fitted in my Network at my new address. The Engineer was good. Alas for some reason he could not get the Hub 5 to connect. So he tried another one and that would not connect either. So he gave me a Hub 4 which connected. I found that rather strange. He left to go elsewhere whilst I connected to the internet. The Hub 4 kept disconnecting so I had to get him to call back. Fair doo's he called back and said there was a problem at the cable on the street and that he fixed it. ALAS! the WiFi in other rooms on my iPhone is low but high in my PC room. The Diagnostic Tool says--Home Network has a few problems. How do I get VM to fix the problems and set up a Hub 5 of which I asked for. I am in a 2 bed ground floor flat in SA2 8JQ. I had to wait 3 weeks for this internet. How do I connect my house phone, not that I use it but it's good for dialling 150 when I need to. THANKS.