Promised a lie now I’m paying more

I was called by an agent saying they are running a promotion they will add data to my line at no extra cost. To my surprise today my subscription has gone up she migrated me to a different line I didn’t not agree to this . I was under the impression that I would still pay the same amount as promised. I want a refund because I was **** to and please wave the extra charges and give what I was promised, thabisile mbele ***. ***