Excel formula

Job ID: 32846908

Budget: $10 – $30 USD

I have 1000 details of contacts. (Email, mobile etc)
Every week, I need to remove a list of 100 people from the 1000 list after they buy a product. It’s a random 100 each time. I cannot figure out how to remove all 100 in one go. I can only do it individually.

I need a formula or method to remove the 100 who purchased from the 1000 list on excel / google sheets