This is a phone scam! These people are claiming there is a problem with your computer and trying to gain wireless access to your computer. Don't give them any information!
If it matters to anyone - technically, these people are not trying to 'gain wireless access' to your computer. They would have to be standing out in your yard to do that. More likely they're trying to convince you to willing let them access your computer through your Digital Subscriber Line (DSL), using a program they want you to download and install on your computer for them - like TeamViewer, Support.me, or LogMeIn123.
In any case, this caller is trying to scam you by taking permanent control of your computer and convincing you to give them your credit card information for nothing. They are lying to you. Don't talk with them. Hangup on them.