I bought a replacement remote and have not been able to link or establish WiFi. The remote is a 300a. The old remote 358wb stopped accepting a charge. Anyone have advice?

Hi there. Sorry about the trouble. Can you please try the steps below?
1. Ensure that both the aircraft and controller are powered on.
2. Please check whether the aircraft has a microSD card. If yes, remove the microSD card and try linking again.
3. Please switch the linking method between “Linking with the app” and “Linking with combination buttons”.
C1 Button + C2 Button + Record Button + Camera Setting Dial
4. If it is invalid, check whether the remote controller has been updated to the latest version. If not, please update it. https://www.dji.com/downloads/products/phantom3-4k
Have a great day ahead.

I still cannot link the new remote. I am not able to connect the WiFi from the remote. I also cannot see anything from the camera when I connect the remote to my cell phone.

The P3 4K is a wifi drone.  The 300A is a lightbridge controller.