[Slippery Slope]

This question has been weighing heavily on my mind recently as I've got four returns on the account as it is. The account has been in good standing for a few years and only recently has there been 3 or 4 returns on it - with a month in between each of them. How many returns do you think are available before they get suspicious or ban my account?

Is there a punishment or account termination after a certain number of returns? Or is it if you're returning so many items within a short amount of time?

I'll also add that I'm wanting to do a ~$500 SE very soon - Do you think they'll ask for a police report or contact the carrier of the package?
It's been about 2 months since my last SE.