Better Bug Solutions Company installed a virus on my computer which locked me out so i could call them to pay... baltimore Maryland

My mother clicked on a popup that downloaded a virus to her computer it in turn locks her computer and begins repeating over and over again with a siren sounding in the background "you have a virus call 1844 5766323. My mom is now locked out of her computer. I called to see who this company is that's surely scamming her. The call goes through and  they wanted me to pay with my credit card in ordr to remove the virus. I asked them to give me their address. I looked it up and it's a public park in Baltimore Maryland.  I let the "manager" John Carr know that I know that their business is illegitimate and a scam and of course he hung up on me.