Don't trust incoming calls, text messages or emails.
Don't trust caller ID on your phone.
If someone calls you asking for information or to do something, ask for a case id or reference number. Hang up, call back on a number you get from a previous bill, back of your credit card, or by googling the company.
If anyone is pushing for something to be done urgently, stop. Hang up, don't take any action. Call a trusted other person and talk to them about it.