Why I won't use AT&T wireless again.

Basically, I have had experienced an inferior product and inferior service. The phone I bought has always had problems, but now has died after 8 months. I have now spent about 4 hours with them on the phone, and even went into their store, but still do not have the problem resolved. This is a lot of time lost, and seems to be either incompetence or deliberate, I don't know which, but I don't care. I am giving up.