What do you small firms or solos with no firm manager or billing point of contact do about client bill questions?

I’ve seen the “how long do you wait to transfer from trust” question. My firm uses software that will apply funds in trust.

Clients get emails with their bill attached, accounting for what was withdrawn from trust, and outlining, what, if anything is due.

I just had a client who I did minimal work on get a bill entirely covered by fund in trust. So it literally says “amount you owe: $0.00” email me:

“I just paid you. Why am I receiving a bill?”

Bruh. You replenished “just” ten weeks ago. And you don’t owe me.

Like, normally, I don’t mind. I’ll spend 0.1-0.2 and by the end of it, they pay the couple hundred dollars or grand they owe me. But I don’t wanna spend my time explaining that he doesn’t owe and needs to read.

End rant.