Complaint about a store?

I have 12 lines in my account, but store advertised me false promotion. I don't want anyone to visit this particular T-Mobile store in Wheaton Mall. The service they give to customers is very very very bad. They attract customers by saying there is a promotion. They charge the customers high bills. If we complain about the high bills, they say that they are sorry they gave the wrong information about the promotion. Then, they process the refund, but they don't want to refund 100%. I experienced this last month. They charged me more than $80.00 for the wrong promotion they did tell me. I went several times for a refund, but they say they couldn't. Mr. Edwin is an employee who advertised me by saying the promotion"there is add one line get the next line free". I have already 12 lines in my account. He said so, Then I accepted that promotion, but after two weeks the bill went to more than $150.00 instead of $25.00. Then I called the corporate office. After waiting hours, the associate talked to me. I explained everything. He said there is no promotion like that in the system. I was told to go to same store. I went there. The same guy Mr. Edwin reviewed everything; He couldn't find the promotion in the system he told me. He said sorry to me since he gave me the wrong promotion. He then processed a refund, but he said that he couldn't refund the restock fees since I took an old free phone from there. I asked him to refund everything, but he said the store wouldn't refund for restocking. I was very mad at that store. I was requesting my refund since the store gave me the wrong information, but they are not ready to refund me. So, I was obliged to write this review so that other people won't be victimized like me. Be aware of their promotion advertisement.