I have been reporting to you about tech support scams for years.  These scams generally involve pop-ups that appear on your computer screen informing you of a serious, non-existent problem with your computer that requires immediate attention by you and for which you are required to pay money for a service you don’t really need.  The FTC has been particularly active in taking action against these scammers including recent actions against sixteen companies participating in these scams.
Recently, however,  a new variation on the tech support scam has been appearing where you get a phone call purporting to be from one of the companies that may have sold you unnecessary tech support services offering to refund your money.  The scammers then either ask for remote access to your computer, a payment to process the refund or personal information.  The call is not from the person or company that may have sold you worthless tech support in the past, but is most likely from a new scammer who got your name and contact information from a “sucker list” provided by the previous scammer.  If you provide access to your computer or provide personal information, this will be used to make you a victim of identity theft and payments made to them to process your refund are just funds thrown away because you will not get anything in return.
Never give your personal information over the phone to anyone unless you have absolutely confirmed that the person is legitimate and needs your personal information for legitimate purposes.  Providing access to your computer to these people or making payments to these people is also not advised.
It is also important to have anti-virus and anti-malware software and keep them up to date with the latest security patches.  However, you should obtain these security software programs only from legitimate companies that you have researched.
It is important to remember that neither Microsoft nor Apple will contact you by way of pop up ads offering tech support for which you will be charged.  It should be noted, however, that Microsoft does regularly issue software security updates, but they do this in automated updates if you have enrolled for this service.  If you receive a pop up ad purporting to be from Microsoft or Apple and have any thought that it might be legitimate, you should merely contact Microsoft or Apple directly at a telephone number you know is accurate to confirm the pop up was a scam.