Final bill not pro-rated

I received my final bill from T-Mobile and to my surprise it wasn't prorated. I was only 14 days into my billing cycle. I spoke on the phone with a customer service rep the day I cancelled telling him that I switched because I have no signal in my house. I was with T-Mobile for 11 years. I was one of the first people to move to my neighborhood and had 2 bars in my house. After the neighborhood was built up and not a single new tower was put up,my signal went down to the point that I couldn't even send a text message. I explained this to the rep and he said he understood and would not charge me for full month of service. I have no problem paying the $100 early termination fee. But paying for the service that I didn't use, or the one that I couldn't use is rediculous.