I've been using Cleartrip for booking tickets online for more than 4 years IIRC and have done enough business with them that they once sent me a vase of flowers. I like their website and the online experience has been very good. I've personally recommended them to friends.
I had to make a visit to Austin this summer to visit the Enthought US office. The ordeal begins there. I made a booking from Mumbai to Houston and back for 23rd July but since the booking was last-minute, the online booking didn't make it and I was called by their phone department. After a round of discussion back and forth (I was booking tickets for for both me and my wife, KD) over a day or so we finally got a good deal. I was told the ticket is confirmed but the next day I was called by cleartrip to say that my ticket was cancelled by the airline! KD's ticket was fine! So, I had to book in the next available ticket category which entailed a roughly 60% increase in fare for myself. I figured that was the least hassle given all of the logistic constraints and went ahead. As usual, they wanted the full cash before issuing the confirmed ticket so I did a bank transfer to them to pay. I had to do this twice given that the fares were changed. This whole process took a good part of two days -- phone calls, discussion, online transfer, confirmation cancellation, rebooking etc. Anyway at this point I had received the a new ticket, but only the original invoice for the charges. I never received an invoice for the updated booking. I needed to provide an invoice for my flight to claim any reimbursements. I called their office twice to ask for the invoice. I was promised twice but nothing ever came.
Once this was done, we found that KD couldn't get a visa for reasons I won't explain here. Now we had to cancel her ticket alone, which I again did. Turns out that cleartrip's phone service is not connected to their online service, so all that you do on the phone transaction never shows up on their website. This is a huge pain for you have to go through the IVR and phone service for nearly anything. They don't even seem to have an email based service. Anyway, I asked again for the invoice and was upset that they didn't send it and expressed the same. I was assured again but it was an empty assurance.
As it is, I was upset that the confirmed ticket was cancelled and that I had to pay a lot more. I had called thrice for an invoice and nothing was sent. I left for Houston on the 23rd and KD called them again (about 10-20 times when she was roaming) during the next week asking about the invoice and the cancellation. Nothing. The staff were polite but nothing got done and we had no news. They apparently needed my account number even though I had done a bank transfer but never bothered to ask me about it before I left. KD didn't have it handy and they said they'd do the transfer. They got an earful from KD too but it was all useless.
I was livid about not being sent the invoice after this long and finally called them from the US on my mobile. I was really upset and was being assured again and was being given some random lame excuses about this. I escalated the matter to the supervisor who also got an earful and promised to follow up. He called me back the next day (and left a message) and in a day or so I finally received my invoice! Phew.
The agony doesn't end here. I still had no sight of my cancelled ticket refund and had no way of knowing how much I was owed, I had no proper bill, and no information on what was being done. I was promised in the cancellation confirmation email that I'd receive the exact refund amount but didn't get that either. Nothing. No news and they had a lot of my money and a return flight to the US isn't cheap!
They did call KD in the meanwhile and she told them to process the payment. After I returned I was called on 25th August. I was eating lunch and they asked me for my account number again. I asked to be called back in an hour since I didn't have it handy. I never heard from them until I called them on 28th and spoke to two supervisors and really gave it to them. They finally got my account number and I hope they make the transfer. Apart from apologies on the phone, they haven't done anything to make amends.
In all, every step of the way was badly handled. Cleartrip has a nice website but their phone department is a complete mess. They've lost a customer.