AT&T review: Over charged

I purchased two extra phones one for each of my grandchildren. I got them flip phones, but when I open them up, I didn’t realize they were so inexpensive.
I decided to go with a really nice phone and returned the other ones. When I went into the store in Central point Oregon, they told me I could no longer keep the numbers associated with the first phones that I had bought. I said that that’s not a problem because they hadn’t even used them.
I was unaware that I was being charged every month for service on those lines that were never used.
It’s been about 14 months so I’m figuring it’s over $1000 of charges. I was offered $150 credit.
That was after about four phone calls to AT&T in a couple hours of waiting for them to return my call. They said they can’t go back that far even though it’s $1 billion company. I am leaving AT&T and I will never be back. I am so unsatisfied with dealing with them.
I do own my part that I should’ve checked my bill, but was frustrated on their app and just trusted that I would be charged the appropriate amount every month. Don’t trust these big companies.
I only went with them because I got talked into it going through Costco. Don’t go with AT&T.