Hmm I would call up ATT and ask them what download/upload speeds you are paying for. Then also explain your issue. It might be a modem or router issue.
They just activated their 50Mb service in my area. Not too pricey, considering business class at 16Mb was only $20 cheaper.
We did have to battle with them to get it just right. Their techs came out to my office a few times that first couple weeks but I'm pretty happy with it now.
It doesn't even crap out when it rains anymore. Some sort of miracle.