Pathetic company with terrible customer service

I rented a movie with Box office, paid the money via credit card and when we sat down as a family to watch the movie it was the wrong movie. It was the 1st movie of a two part series, but I expressly rented the second part. I lodged a query through the online chat, spoke to four different people and encountered a pathetic attitude and my query has still not been resolved - 3 weeks later. Can someone at this damned company help me? I have spoken to Nicollete, Maroba, Prosperous and Charlotte. Do I need to get in contact with Cyril next? FFS!