Hello nikarsena,
Sorry to hear of the broadbadn speed issues experienced over your parents wireless connection, we understand the frustration this can cause and appreciate you raising this via the forums. Welcome to the community.
We would always recommend using a wired connection wherever possible for the fastest most stable connection. We appreciate this isn't always possible and depends on the device, distance from the Hub etc
We have these tips available to help with broadband issues:
When running a speed test we would always recommend running this via a wired connection This can be completed using an ethernet cable via a PC or laptop and will allow us to see the speeds available at the Hub.
We do have the Connect App https://virg.in/connectapp that will allow you to scan your property to optimise the wireless network and if needed order pod's. Depending on your package these may be free but any package is eligible for these if needed.
You can also give the team a call on 150 from a Virgin Media landline or 0345 454 1111 option 1 then option 2 this will get you through to the Broadband technical team who will be able to look into this further for you.
Rob