I used the exact amount on my apple cash now im negative

I had $11.88 on my apple cash debit card. This card isn’t one that gains money from an apple card but just the cash one i use for sending and receiving money. I filled up at a kwik trip gas station and put exactly 11.88 in my tank, i hit the no receipt button and went home to see i got charged the correct amount but my balance had been negative for days at -10.50 with no other charges. I have reported the charge at kwik trip and yet nothing to come, but i’d like my apple cash to work without me having to pay in $10.50 to use a feature i should have for free.