Dell technical support scam

I bought a dell XPS a few months back and I had to call Dell technical support later because I was sent the wrong product (one without a touch screen when I ordered one with the touch screen). I had to go through the technical support initially to trouble shoot and show my computer did not have a touch screen. A few months later I kept getting calls from people who claim to be Dell technical support (with an Indian accent) stating that my home network/IP address is under attack from hackers. They had all the information I shared with dell technical support initially (my name, phone number, email address etc.) as well as a work email username/login user name which I did not share with the tech support person (but this user name has been used in my laptop by the time I called dell tech support). Tech support( initial call, when I called them) asked me to install a remote app to browse my computer which I did at the time and I had used this login name on my laptop by that time although I did not provide him with that.

So far I have received two calls from people who claim to be dell tech support after this (months apart, both Indian accent). One call came from a dell number (when I looked that up in google) and sounded very legitimate except that I found it a little difficult to believe that dell monitor my network and make unsolicited calls claiming that my network is under attack . They wanted to connect to my computer but it did not happen as I was away. They even gave me a call back number which was Dell ( although I did not call them back).

Today I received another call from a person claiming to be dell but the caller ID was hidden. This call was much more suspicious but they still had all the info I shared with the original Dell tech support.

My questions are;

Does dell make unsolicited calls like this claiming the networks are under attack?

How do these people get hold of information I provided the Dell technician with? I was assuming my information was handled in a secure way.

Lastly these people had access to a login username I use at work (this is a very important account and the breach of it would be extremely dangerous). This username was in my computer when dell browsed my computer using remote access, and I did not give the dell technician this user name.

My computer has always had an antivirus (updated) and I changed my network info recently and have an administrator account on my computers so installing apps without my knowledge is not easy.

I always had a high regard for as a company as well as their product. But this experience made me think twice. I am not sure its safe to use Dell technical support anymore if these were really scam callers, as these people seemed to have gotten access to my info after calling dell technical support.

Thanks!