Bad customer experience

I made payment arrangements with supersonic, they calculated the amount needed to pay in black and white.

After making the payment I was told that I will not be connected before settling the full amount. I agreed to the their terms but asked them to minus the months I was disconnected.

Why did they send me the email with the arrangement knowing that they will change the agreement.

I asked to speak to a senior to check what was sent to me but as usual the Team Leaders are not available to assist, I also wanted to report the agent that dropped the call while waiting for a Team Leader but again I cannot fault the agent if the Team Leaders refuses to take the call.