Help getting started with Roku devices, including setup, connecting your device to your TV, linking a Roku device to your account at my.roku.com/link, adding channels, subscribing to services, and more.
You reached a scam site. All they want is your money, or to sometimes connect to your computer. They would not have done anything to assist you, other than take your money. As Tanner mentioned, genuine Roku support will never request a payment for assistance, nor will they ask to connect to your computer remotely.
We might be able to assist if you provide some details. What model Roku devices do you have? Numbers, not names. Did they all fail to connect at the same time, or did each device lose connection at a different time?
In the Roku settings menu, I believe under the advanced system settings, there is a Reset Network Connections selection. Try that on one and see if it will now connect.
Dan Roku Stick (3600), Ultra (4640), Premiere (3920), Insignia 720p Roku TV, Sharp 4K Roku TV, Nvidia Shield, Windows 10 Pro x64 running Serviio and Plex on a wired Gigabit network.