Horrible customer service experience

So very frustrated and disappointed by this customer service team. I am now on round 5 of trying to have promised promotions applied to my bill. I have been bluntly lied to by agents giving misinformation about upgrades etc. and threatening "high fees" if I went over my data limit (I have unlimited data, which they also gave misinformation about) I have been told credits and promotions were applied for them to never show up. I have had agents just leave the chat on SEVERAL occasions. This last experience has been even worse. I am now 3 hours into conversation and 10 agents as they have continued to transfer me with no communication or solutions.