Pitiful Service/ Insufficient knowledge from Help Desk

I have tried to purchase electricity through this web site three times, and every time the amount is blocked on the credit card, but the transaction on the web site fails. When this is queried with the help desk, the answer is that the problem is with my bank , which is total nonsense. Last time, after lengthy discussions and arguments, I was promised that the situation had been rectified.... only to happen again. Now I have to wait three weeks until the funds get released on the Credit Card again. Completely useless.