Twice now this has happened to me. I went online to make a payment towards my EIP. No problem, everything looks good. Then get my monthly bill. It's only for about $8! Well that's strange so I log into my account and see that the $100 that I "thought" I paid towards my EIP, was actually credited to my regular bill. So now there was no change on how much I still owed on my EIP. Ok, not the end of the world.
In January I see that I only owe $100 more on my EIP. I go online to pay this off in full. Everything seems fine. Today (March 10) I log into my account to see that my March bill is going to be $188! It should only be $88. Turns out that Tmobile yet again, counted my EIP payoff amount to my Feb. bill and my Feb bill was only about $8. So then the March bill ended up essentially being for two months.
Don't think I'll be doing another EIP again. And I hope this post alerts others to make sure your payments are being credited correctly!