Myntra.com — Myntra credit stuck problem

My myntra credit is stuck as I had logged in using my number which is a new number [protected]. It did not give me an option to update my e-mail id. However as I was about to place the order using a gift voucher, the gift voucher was added to the account but could not use it as the OTP was sent to an e-mail which I did not even register. The e-mail id was [protected]@sofimail.com which I found out from google is a temporary domain. I guess it is some fraud that myntra is doing. I really want this to be resolved as the amount is 3000 and it also had an expiry date.