Client added funds, now showing as credit - cannot apply to invoice?

[nf_able]

Hi I had a client apply funds to their account for an invoice (not sure why they just didn't pay the invoice itself)  but I am seeing they manually added funds for the balance of an existing separate invoice (first image in my attachment), in the transaction under that invoice in the admin, it shows amount paid by Credit/Debit, then immediately under it 'Credit Removed'

Second image in attachment is the invoice they should have paid on - it shows balance of $0.00 and under subtotal shows 'Credit: $1750' the amount owed on the invoice they manually added funds for.

Third image shows their account has $1750 USD credit available.

Client summary (not pictured) shows

Paid	3 ($1810.00 USD)
Draft	0 ($0.00 USD)
Unpaid/Due	1 ($0.00 USD)
Cancelled	0 ($0.00 USD)
Refunded	0 ($0.00 USD)
Collections	0 ($0.00 USD)
Income
Gross Revenue	$3560.00 USD
Client Expenses	$0.00 USD
Net Income	$3560.00 USD
Credit Balance	$1750.00 USD

When 'Paid' should be $3560 ??  How do I get that $1750 credit into my bank?  I can't add that to the original invoice 'error: cannot apply more credit than the invoice total"

What am I missing?  It looks like they have $ that is in limbo in the system that won't come to me as cash.

Thank you,

nf