Bounce Energy

I was given a 75$ bill credit when i switched my service to bounce energy as i was referred by a friend and it was in the month of september. My service started on september 2, 2015. the 1st time i called customer service regarding this credit, they told me that i would receive it after three consecutive on time payments. i made three consecutive on time payments as they said and called them up regarding the same issue before the final bill was issued, they told me that the credit would be reflected in the final bill. Then after they sent me the final bill without any credit in that. I've called back the customer service regarding this immediately they told me that a ticket is registered on my account for the bill credit and it will be processed in 2 to 3 days and now its almost been 20days and i've called them every 4 days till today they say the same that the ticket is registered and it will take 3 days and when i ask them to connect me to their supervisor they say either the supervisor is unavailable or say that he will call you back in 20 minutes but till today i never received a single call from them and today is my due date and i call them today also they say the same that ticket has to be processed. what i do now? why did they give that offer then when i joined. i have the screenshots too of everything. this is been ridiculous now. could anyone please help me out with it.