account going negative

it’s really weird lately my account has been going into the negatives.. I don’t overdraft at all. whenever I purchase something it’s taken right out. i’ve gotten nothing stating that I was sent a refund I ordered bath and body works but it has shipped already.. other transactions are pending but was immediately taken out from my available and is pending at the bottom. small amounts of money have just been appearing in my available and when I spend it then it goes into the negative more than the amount I spent? i’m so confused…