Dell has no fraud department? I believe Dell has been hacked

I have received over 30 calls in the past 2 years saying I had problems with my computer and they were calling from Dell. Which I knew was a lie since I had called Dell over 85 times regarding computer problems.  But what was disturbing me is that they had the model of my computer and the email address which I only use for Dell no other company.   Yet, today I get a call saying they are from Dell Account Services the person said her name was Tracy, she had my computer Service Tag Number, she said that Dell no longer required warranty on their computers and was giving a refund back of $250, I do have an extended warranty but I did not disclose that to this person.. I talked to an *** about this and he said that yes indeed that this company has either sold my information or the company site has been hacked. I called the warranty department 4 times and they hung up on me.. Technical support could care less. I called the Sales line and was given a number and it was not for the Fraud department. No one else in this world has this particular information about me except Dell. I am every concerned that I can not reach anyone regarding this matter.. I think this is a serious problem. The other calls I could handle but not the one that knew my service tag number something is very wrong here and I want an answer.... ASAP