Poor poor service

This is by far the worst app to buy electricity. They've blocked me twice already and say I owe R138,50 on each account it has happened. How do I owe if they sell "Prepaid Electricity"?. Just on Friday last week I wanted to buy electricity for R100 and I couldn't , but eventually it came right only to come today as I want to top up and I can't because I'm blocked AGAIN. The lady couldn't even answer my questions properly. How do I owe if the money deducted from my account? They say it bounced back, but I got nothing back. Their service was not good and I just won't use them again. They need to work on it, because this, this is frustrating. What if I don't have that R138. 50 to pay and unblock, it means I won't have any electricity because they blocked me and say the money bounced? I hope this is not what they doing to everyone as well.