Here is my latest experience with Temu.
I ordered a 4-pack of rechargeable batteries for my husband's flashlight.
The package was sent from Temu's American warehouse and arrived yesterday morning. It only contained one battery. I double checked my order and confirmed that I had ordered 4, not 1. I decided to let it slip because I just didn't have the time to deal with it.
Today, a package arrived in my mailbox. I live in Upstate New York, it was shipped overnight from California with high priority mail (not cheap, overnight shipping with USPS costs an arm and a leg and then some).
The package contained a long letter of apology for messing up on the number of batteries. It also contained 4 batteries plus a free flashlight. It also said in the letter that I was welcome to keep the single battery too, so I got 5 batteries instead of 4, plus a flashlight.
I never contacted them. They must have some check points in place and detected the mistake.
Now, this is what I call excellent customer service.