The reason why Guangfa Bank owes more than 60,000 yuan with a line of 50,000 yuan is because it includes loan interest. The loan amount of Guangfa Bank is different from the amount owed, because the loan interest and other expenses will be accumulated during the repayment period. The loan interest is calculated according to the loan amount and interest rate, and the interest is fixed monthly. If the borrower fails to repay the loan on time, the interest and penalty interest will be accumulated and added to the outstanding principal, resulting in the amount owed exceeding the loan amount.