@cam2363 is correct. take it in for an exchange immediately. (most places have a week or two straight exchange policy)
if you're interested in attempting the repair, follow below.
Please be advised that myself, nor this web page can be held responsible for damage to any device, should an attempt at repairing one's own device fail. Always make sure to consider hiring a professional repair shop to fix your device for you.
Diagnostic steps for not charging:
1) Check for a blocked port (Lint build up can keep a cord from fitting in properly. if the frame of the plug is not flush with the device, using small tweezers, and being careful not to damage pins, pry out any dust or lint.
1) Try a Known Functional Cord. (Works on another device)
2) Excite the battery: Hit the + and - of the battery with an external power supply for approximately 10 minutes. (Be sure to verify you are using the amperage and voltage that the battery can handle. (Located on the battery with the specs.)
If the device boots, then the battery is functional, and you can continue forward with your diagnostics.
3) Scan board, and Flex circuits for physical damage. Looking for signs of blown or chipped components. Scorch marks, or corners of components broken off. Replace as needed, and test again. A 10X+ microscope assists very well in this stage
4) at this point, plug in the device again, and check if it charges. if it isn't, then go forward with replacing the charge port itself.
5) if replacing the charge port does not fix the issue, then you are experiencing an IC or board failure, in which case, it will just be better to replace the device.
I hope this guide has helped you in your diagnosis.