how is returning an item suspicious if I may ask. I'm not keeping the item. I'm sending the item back. If anything it causes me inconvenience to have to ship it back to them.

At what point do they issue the refund? If it's before they actually receive the returned item, then there's your problem.

The question here really is why does returning defective items trigger flags? Both returns were acknowledged by Amazon has not my fault and return shipping was paid for by them.

But it's not just returning defective items. Aside from the fact that, from their point of view, they only have your word that the items are defective, it's three high price items they've refunded in quick succession. Hell, if I were building an automated system to detect fraudulent transactions, I'd sure as hell be looking for patterns like that.

I'm not taking this personally but I am bothered that a company would single out consumers who have had issues and basically say fuck off.

See, when all you take from that email is thinking that Amazon have told you to fuck off, that's taking it personally. It's an email which is effectively saying "we think your account is suspicious, so we're placing limits on it. Here's an email address for you to contact to get this sorted out". How is that treating you like a problem child?