If its above 30 then its within VM's "wifi guaranteed" speed range. So you may struggle to get any help from VM.
If you want to do something about it yourself - see this.
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To address the wifi issues, VM now supply “wifi Pods” (no longer doing cheap and cheerless and poor value “boosters”). However, their Pods are only free to customers on the 1GB, Volt (or old Ultimate Oomph) packages - is that you? If so they are worth trying - they should work for you.
VM Wifi is now “guaranteed” to 30 Mbps/room it’s now called… Wifi Max see link
https://www.virginmedia.com/wifi-max
... but as yours is over 30 they wont be free to you… you will be charged £8/month for up to 3 pods. It’s a simple solution and should work for you. However, you would soon pay off that cost by buying your own wireless solution that will be yours to own and use forever, although the VM Pods should be a simpler option. If you do want to invest in better equipment, you would need to get either a… (1) Mesh System, (2) Wireless router, (3) Wireless access point(s), (4) a pair of good quality Wifi Powerline Adaptors, or a combination of (2&3). £40-100 (that’s ~4->12 months of Max Pod rental) should sort it for most customers with an average property and usage. Spend more for additional advanced“features” - if required.