Call from Netgear today

Hello, I received a call today from someone saying they are with Netgear support and they found that my Netgear is trying to be hacked and that could be the reason my internet has been slow. They said they would need to login to my computer and I said I do not allow anyone to just login to my computer without confirmation that they are who they say they are and I asked for a phone number to call the Support back for Netgear and they provided 276-262-2927. I just am not sure if this is a scam and when I try to call Netgear's support number on their website they (not the number the caller provided) Netgear will not speak to me because they say my support for my product is expired but all I want to know is if they really are trying to call me regarding this. I do not understand if it was a scam call how anyone would know I have a netgear modem/router and get my phone number but again and also would Netgear really be monitoring my connection to see someone is trying to hack into my modem? I called the number back from my work phone so they would not know it was me and the person just answered by saying hello and when I said, who is this they said, hello and acted like they were support again. I need to know how to reach Netgear to find out if they are really trying to call me about an issue with someone trying to hack me. I have been having issues with slow internet and even for the first time ever last month went over my bandwidth and could not understand how, I fought with Comcast telling them something is not right with the data usage because it just was not possible but they said because I use my own modem they can't look at what devices are using what. Anyone have any suggestions on how I can confirm with Netgear if they are really the ones who called me without me having to pay for support just to speak to them about this call I received?