I've read a lot of comments from Globe subscribers saying they received a recycled phone number from Globe. I've also been a victim of this process when I got a Tattoo plan from them. A friend is also experiencing the same. She already had her phone number changed about five times because of this but still, she's still receiving calls and texts from people she doesn't know. The previous owner of her current number is a barangay captain so you could only imagine how many people calls/texts her everyday.
You might also be a victim of a recycled phone number that's why you've been receiving those calls and texts from people you don't know.
If you only recently acquired your phone number, I suggest that you call Globe to have your phone number changed to avoid same issue in the future. They should waive the 500-peso admin fee since it's not your fault you want to change your number.
If that is not an option, you can also call Globe to have them block the stranger's phone number from being able to contact you. However, they can only block Globe numbers and not numbers from other telcos.
Another option is to download a call/text blocking app. iOS devices have a blocking option by default.
If you still want to report the phone number as SPAM, you can go to this page: Spam Message Report.