Why would my lawyer send me a letter vs calling/emailing?

I had my hearing about 10 days ago. During my hearing the VE stated no jobs found.

About 6 days after my hearing my lawyer did call to ask about an appointment that I had at a urgent care ortho clinic where it was found my arthritis has worsened in my spine & I needed an MRI to verify what disk are destroyed as it was 5x worse than my last xray & mri which was bad in itself at that time.

I had to remind the lawyer that was the appointment I told him about the day of the hearing & how I can’t get the MRI due to not have the $150 for the co pay on it. And that was the end of our call. This morning I see I am getting a letter delivered via usps from my lawyers office… but my dang post office worker placed a vacant sign on my box so the letter wasn’t delivered(I barely get mail so I’m assuming they thought it was vacant even tho I had 3 letters to be delivered this week alone)

Now I’m freaking out because why would a lawyer send me a letter vs just calling me. Did I not get approved? My portal doesn’t show any updates & as of Thursday no updates per the call center rep.