When signing in to request help from Apple phone support they ask for the serial number on your device. I put in the serial number listed under "About This Mac" and it will not accept it saying, "this serial number is for another device". I triple checked the number and triple checked my entry to make sure the number is correct. What can I do next? Thank you so very much for your help.
Your best bet is to call Apple at 800-275-2273 - did your Mac have a major repair at any time? A new logic board will always have a new serial number for instance.
See what is listed here...
Is this new? Did you buy directly from Apple or from a reseller? It sounds like a reburbished device, and Apple refurbs have the proper number.
Next step: See if the numbers you can access agree.
1) Do "About this Mac.." from your Apple menu and record that serial number:
2) While still in "About..." click the "system Report" button under the serial number to get this:
Record the serial number that will be where I grayed out the results.
3) Flip the computer over and find the serial number in painfully tiny print near the hinge. There are at least possible formats, maybe more:
The upper image is a 2012 model; the lower is a new 2020 M1 Macbook Pro,
⚠️ Without posting those numbers here (for security reasons), do they all match?
If the number on the case (#3) does not match the numbers in methods #1 and #2, then I suspect Babowa has the correct answer and you were not sold a new computer.
If all three numbers match, then Apple will have to sort this.