I booked the
ticket and did the visa on arrival with the documents I had received from [edited]. I
applied for 1 day rush and received my work visa the next day then entered China.

I assume you arrived in Hong Kong to acquire your visa, and I suspect it was not a Z visa. U.S citizens cannot obtain Z visas in Hong Kong.

If you entered the mainland on any other type of visa, you were working illegally in China. Thank you for notifying everyone, including the Shenzhen police, that [edited] facilitated your illegal entry.

You are lucky. Many FTs have been swept up in Shenzhen by raids on schools. They are held in detention, fined and deported.

Would you care to provide us with the name of the school? They too deserve recognition.