If you unsubscribe from Passfolio Pro, you will no longer be able to borrow more money. However, if you had previously leveraged your account by using margin, you will keep the money borrowed and will continue to be charged interest on it. If you want to return the money, you can do so by selling securities worth the amount of money you borrowed or deposit funds to cover the debit balance..
You deposited $5,000 to your stock account, therefore had available an extra US$5,000 in Margin. You bought $6,000 in Apple (AAPL). On this purchase, US$5,000 of it came from your cash deposited and US$1,000 came from your Margin Available. Once you unsubscribe from Pro, you lose the remaining of your Margin Available but you keep and will continue to be charged on what you had already borrowed. To return the money and stop paying interest on it, you must sell Apple stocks worth US$1,000 (plus any margin interest charged), which is the amount of money you borrowed from Passfolio.