I just reached 55 two days ago but they told me I am not eligible to receive my Senior discount

Thanks @amazinggracelady for posting that chart! It is a great resource for this conversation. It is still accurate. The Magenta and Magenta MAX 55+ plans do allow 4 lines. The Essentials 55+ only allows 2 lines. 

@Happy_Friday I sincerely apologize that our teams got your hopes up about that senior discount. You really are getting the best rate for the 4 lines with the Essentials plan you have because upgrading to one of the 4 line 55+ plans would cost you a minimum of $20 more per month.