Non existent customer relations department

I had booked a flight for Durban in December with BA fairly early this year. I timed it so that my car hire would work out to exactly 5 days and that I would arrive in Durban and be able to check in to hotel immediately. While I was away on an overseas holiday I receive an email stating my flight time has changed to 4hours earlier. I chatted to the consultant who advised she tried to contact me telephonically, which I accepted. I then told her I am unhappy with flight time, as now I would be out of pocket, because my car hire would have to be extended for an additional day. If I choose a later flight, I would lose the whole day and only arrive at hotel around 6pm. I then proceeded to email the customer relations department with my complaint. I received a call acknowledging my email, and was advised that they would contact me the next day. A week later, and 2 reminder emails asking for feedback, I have still heard from no one. I am so disappointed in the lack of urgency. What is the point of an after sales team if they are just going to ignore concerns and queries from customers!