I think it's quite normal with DJI service. Below is my replacement battery waiting time: 21 days. I didn't send back anything, just the log contained battery cell broken message. And it took about 2 weeks from Dec 29th to arrive.
I have sent all items comes with my fly more combo package to the DJI. Today I came across to a YouTube video and I totally understand this guy's frustration. I hope my story won't progress into a horror story. Dear DJI team, I want my aircraft to be repaired or replaced, but there was no problem with my controller, chargers and original DJI shoulder bag. Thus, I want these items back with the repaired or replaced aircraft. They were brand new and used only 2-3 times.