I interpret the details as indicating that $700 was used to pay medical expenses via the HSA debit card and that $300 was taken out of the HSA via the ATM. If so, you an apply the $300 against any unreimbursed qualified medical expenses not paid directly from your HSA that you incurred [in 2016 or in an earlier year] after the establishment of the HSA as long as you can document those expenses.
