Shocking...but not surprising. ![Embarrassed :-[](https://www.eevblog.com/forum/Smileys/default/xembarrassed.gif.pagespeed.ic.zcm3EmNu9T.png)
I think I need a better dictionary
![Wink ;)](https://www.eevblog.com/forum/Smileys/default/xwink.gif.pagespeed.ic.cldandycH0.png)
After all, the meter is (probably) accurate within spec and you have your certificate in hand. They're probably genuinely perplexed as to what the problem might be.
This attitude would be more understandable if it wasn't coming from a company that makes a 6.5 digit bench DMM.
Is the serial number physically on the back of the case as well as shown on the display? And now they don't match? ![Face Palm :palm:](https://www.eevblog.com/forum/Smileys/default/xfacepalm.gif.pagespeed.ic.EBDwh1hCfo.png)
Correct, but it's a sticker on the back of the case, and I have a label maker...