Extremely Slow Internet

I have been promised a 4Mbps line, yet my internet is at 0.4Mbps. I can't even stream a YouTube video at 480p. I hope this poor quality service will be fixed, or it will result in the company facing a lawsuit (Not from me) for promising false deals. There's a lot of people complaining about your internet speed and it's bad publicity for the company. Why sell us something you cannot give us? Think about it.