Clay Telecom — mental harassment

I got a sim card from Clay Telecom for my parents travel to Europe for 10 days. They said they wanted my credit card details only for security reason and would block rs 5000 as a company policy. 2 days post returning the sim card, they sent me a bill first with the wrong dates, when my parents were still here in India. Having got that corrected, after several calls to the customer care, i get my card bill with that amount being charged. I again had to go through the process of calling them and explaining my case and proving with the customer sheet i had that it was wrong. Its such a mental harassment to deal with such . Spare yourself the pain o[censored]sing Clay services !!!