Horrible Customer Service Experience with AT&T Prepaid

I have ATT Prepaid for a very long time and i decided to switch plan to $65 unlimited on August 1st, everything went well and i was charged full price $130 for  2 lines. So on September 1st my plan suppose to be renewed for $100, 20 autopay discount and $10 multi line discount. But i was charged $120 and no auto pay discount provided. I called ATT and was told that the discount will be provided next month and make sure Auto-Pay is on which it was all the time. I asked to speak to a supervisor but she told me that he/she is at the meeting and will call me back, of course he/she didn't. So i called again and the guy said sure no problem i'll fix it and put me on hold. Did something on my account and my two lanes became inactive and i got disconnected from customer service call. Called again and the lady finally activated my lines and charged me again $120. I told her you charged me twice today. Being on the phone for more than an hour she game be back my credit. SO now still i didn't get auto-pay credit for September and i am even afraid to call again not to loose my lines. The experience was horrible.