TIL: AWS Charges for Failed Multi Part Uploads to S3 Which You Cant Find

We at CryptoGround (https://www.cryptoground.com/)use AWS S3 backup for backup of our DB & Files. We do a backup every 6 hours. Our backup files are of around 400-500 (we do code backup + DB + all images). We store around 10 backups and delete rest. So it's around 40 GB usage but every month since few months we are being charged for 4 TB usage.

I tried to contact so many time AWS support but no one responded properly. Finally, one CS guy said you are being charged for failed multipart uploads.

That is if you try to upload a file and it's partially uploaded and it got failed then they do not delete that file nor they show it anywhere in the S3 panel that there is so much of failed multipart upload.

And they gave this solution:

To resolve this, go to the bucket, click on management, go to the life cycle, and create a policy. Set it for their entire bucket, skip the transition page and under the expired page, set the rule to delete multi-part uploads after 1 day. This should clean up the buckets. (They need to do this for all buckets).

I googled a lot about this and found there are similar various hidden charges which gets charged if you do some minor mistakes and they are not easily reflected on the invoice.