Numerous issues with my account since adding a new line

I have been with AT&T for many years on a plan alone. I wanted to add my husband in February and did so after chatting with a customer service Representative online from AT&T. I received the new phone I brought him in the mail and he activated it in store on Feb. 8th. I was even told the activation fee would be waived. Which I do believe it was. Yet I have had numerous on going issues since adding this line. My bill is much higher than I had anticipated, I was quoted it would be around $130 a month before taxes and fees. I am paying $170. The first bill which I know includes pro rating and I except to be a bit higher was over $300. I did get some help with this at an AT&T branch in valdosta GA. It turned out when I added a line my existing plan did not convert to the family share plan, but stayed on my account and a whole additional plan added. So I was paying for 2 accounts. The Nation 450 plan was removed once it was discovered what had happened, and some amounts credited to my account. I really can not keep up with it because AT&T's billing is like pretty close to rocket science to me. Anyway I was okay with that solution then here comes the next issue another bill for more than I expected. I stopped by a location in Athens GA and was helped by an EXTREMELY AWESOME customer service agent (Larrissa). She was amazing and Rodney the store manager help some also.  Well it turns out that bill was so high because the other one was not paid although I had auto pay and received a text it had drafted. I could accept that, but my final issue is the fact I was informed I was put on a family share plan that had expired, it was an older plan that cost MORE for less data to share between the two lines. I was quoted around $130 for a family share plan with unlimited talk, text, and 8 GB of data to share, but somehow I am on a plan with 6 GB of data to share and paying more. I was told I wanted to be on the plan I had chosen when I chatted with the customer service agent and went through the steps online. I was told I should wait to call when my billing cycle ends so I don't have to pay pro rate chargers again. The thing is I don't think I should have to pay for pro rate chargers or wait to have the service I choose in February. Also for feb, march, and april I have been paying $40 more than I was quoted when opening the other line. It would have been cheaper for me to have 2 separate accounts lines instead of what has happened since adding a 2nd line since my bill use to be around $81 total with taxes and fees. 

I was thinking about just contacting a different service provider that offers to pay early termination fees and switch to their service, but I thought I would give AT&T a chance to make this situation right. I love the company, but this is an ongoing issue. One after another with my account not being handled correctly with having 2 plans, then an expired family plan that cost more than the one I choose for less service. 

In moving forward I would like my plan switched to the one I choose as soon as possible and my account created for the months I paid $40 more than I was quoted which would be $120. I do not feel like going to a store location will resolve this issue. Last time I went I was in the store over an hour and was told to wait until my billing cycle ends to switch plans. I should not have to do that and I should not have had to pay $40 more the last 3 months. I would like to know a customer service number to call in an effort to resolve this and remain an AT&T customer or I will have to switch my service provider in the near future.