Hello, I’m Nathan, and I’ll be assisting you today. My livelihood depends on your positive feedback, so your satisfaction is my highest priority.
Sorry to hear you’re having trouble.
As long as you bought the same handset model (the B or S at the end only indicates color), it should be compatible. However, it doesn't work right out of the box, there are some additional steps required to register the new handset to the existing base station.
Initially, grab that new handset, and press MENU #130then go to the main base station, where you'll press and hold the Locator(intercom) button for about 5 seconds, until it beepsthen press OK on the handset, and it will sound a long confirmation beep