Energyhelpline.com - no cashback

thanks

I used energyhelpline.com to switch both my gas and electrcity in May last year and received an e mail from them with all the details of the switch. As I didn't receive my cashback, I have been e mailing them a number of times. They have been repeatedly reassuring me they will be paying the cashback. Now they have stopped replying to my e mails. I don't know about others experiences but I will never use them again.