Legal action for non payment from a NYC dispensary?

Not sure what to do.
I own a very small, organically grown cannabis microbusiness in the northern Catskills. It’s been slow going as I’m a sole proprietor with a few field hands during the growing season.
They are paid from crop sales and I recently ran into a major snag.
I sold roughly $4500 worth of product to a dispensary in NYC. The agreement was 5% off (in addition to other discounts) if COD via ACH transfer was made. I took a picture of their accountant’s screenshot with the proof and went on my merry way thinking a deposit would be in the bank writhing 5 business days.
It’s now been 27 days and no deposit.
From the buyer:
“There has been a backlog in accounts.”
“I’ll look into this.”
“Accountant is away this week.”

When is it time to threaten legal action?
What can I do? My crew should get paid for their work!

To open the wound more, the manager asked me for images to help sell the product on their screens. I told him I wouldn’t provide anything until we get paid.