T-Mobile vending machine cheat and no returning of my money

I tried to make the payment at the T-Mobile store vending machine. But it got some white screen and resetting to the default screen. So, I filmed the situation. Later, I put 200kuna into the machine and the screen turned out to the default screen! And it showed no sign of my money to be in the deposit at all!! But I complained it to the clerk and the clerk fixed the situation by just asking me to pay the extra money for the payment only. So, I paid the right sum and it was done. I thought my 200kuna bank note was stolen by such hacking of the vending machine.