I recently have been having the same problem. I have a unlimited plan with an iPhone 6 and my data has been horrible lately. Used the speedtest app and got the the following results:
date [download / upload / ping]
09/25/14 [0.14 / .014 / 604]
10/08/14 [0.03 / 1.05 / 70]
10/09/14 [0.13 / 0.00 / 245]
10/16/14 [0.53 / 0.41 / 47]
10/27/14 [.051 / .046 / 48]
*I always have min 3 of the 5 antenna dots
I used to always get 1.5mbps down and 0.5 up once the intital 5gb of LTE was used but now it looks like they cut the d/l speed a lot. I can actually deal with 1.5mbps throttle. it still allowed me to stream music, surf the web and get my email fine. I ended up reaching out on twitter and then spoke to a rep who had me check a att.com/tt address and since it pulled up, the tried to end the call. I said the connection was not the problem, it was the speed. She had me pull up google and it took 123 seconds to load...123 SECONDS TO LOAD GOOGLE!!!! So then the rep tried to get me to switch off the unlimited plan so the conversation ended there. My billing cycle starts on the 2nd of each month and as you can see, my speeds were getting throttled 6 days later (10/08) to .03mbps. Like I said, I don't mind the trottle, I do mind paying for a service that is clearly not working. Do I have any recourse for paying for a service that I am not receiving?