Yup. I had a similar suituation as well few months back. And then, I left using muncha.com. My username and password doesn't match at all and when I tried to request for a new password using security question. It says incorrect as well. So, I was freaking out a little bit at that time. And, I used thamel.com and I find it more friendly and easier. Apart from that, it gives higher rate compare to others as well. 

Note: My personal view only :)