This answer to this question -- "Where can I write a letter to AT&T?" -- is far too difficult to find. This should be in the "Contact Us" information on the main support page. Not everyone wants to talk on the phone, chat with someone, or send an email. Some people still prefer the good, old fashioned way: writing a tangible letter and dropping it in the mail. There should be a correspondence address listed on your main page instead of just a billing address.
Looked at my bill this morning and it was 229.07, last month it was 153.00 and 191.00 the month before. Called in and the reason for the 153.00 is because they forgot to bill me. So the charged me double this month. Then to come to find out they increased my data usage from 3 gigs per month to 6 gigs, So I did not approve this told them I barely use 1 gig a month, they said my bill would only go up 5.00. So I told them did not want it or need it. So they changed it back. So from spending 190 a month I am not 218 go figure that out. So it looks like I can not stay on the plan I have been one, so they have to change it to make more money and if I want to go back it is going to cost me more money. This is not a good company. I have been with you for nearly 20 years before you were at&t and this is how you treat your customers.
So I will be posting this on many media sites to let people know and I will be looking at moving away from your company
Unfortunatelly the mobile share advantage plans were modified this way and the old plan you had was expired, however, if you use less than 1gb , you can Contact at&t and ask for the mobile share Flex 1gb plan that avoids overage, you can use more than 1gb at lower speed and not get extra charges billed, also this plan comes with auotpay/paperless discount which will help you to save more than with the 3gb plan you had, this 1gb plan cost 35.00/mo before discount + access fee + tardes + other charges you might have like insurance, installment plan, etc.