Dear John: Everyone talks about how great Amazon customer service is, but be forewarned: if you buy an item on the Amazon Marketplace from a third party and need support — a refund, missing parts, etc. — you’re out of luck.

I would understand if you can’t help with this, as it dates back more than a year. I never thought to bring it to your attention while it was going on.

My wife and I ordered a bar cart on Amazon that was being sold through an outside company for $119.50. The package arrived, but did not include screws to put it together. I inquired with Amazon to get the screws, and they directed me to the seller.

As Amazon continued to direct me to the seller when I tried to follow up, I disputed the charge with American Express. That was unsuccessful.

Can you help me get the $119.50 back? The money will go toward diapers for my new baby son — due in a week! C.S.

Dear C.S.: I assume the baby arrived by now. Congratulations!

I spoke with Amazon. There was apparently a mix-up that I agreed not to discuss.

Bottom line: You should have heard from Amazon’s customer service people by now and your problem should be resolved.

For the record, I buy a lot on Amazon and very seldom have problems with returns. But problems do happen.

That’s what keeps this column in business.

Go, I hear the baby crying.