Misleading British Airways

Shocking what BA did to me!!! When I booked a flight from Johannesburg to Cayman via London for 1st Jan, I asked what happens of it gets cancelled they said don't worry there is flights the day before and after. Now they cancel my flight and say a flight is only available in 2 WEEKS. Great service for a business class customer?

Then it became 10 times worse. Because my flight was cancelled and had no flight I had to just get myself on some flight so they put me on the 2 week later flight because they said that is all that is available. Before this was booked I told them I am not happy with the date its just to secure a seat but I will change it later or at the airport as that is what they recommended. Later I noticed on their site there is a flight available much earlier. So I phoned to make the change and they say no I cant make the change as it is voluntary or have to pay $4,000 in additional fees (twice my original fee) if I want to make the change. This is all because they canceled my flight and they did not mention if I make a change I won't be able to make a change again even though I mentioned to them i'll make the change only to get on a flight but I will need to get on an earlier flight. After I asked to speak to a manager the person on phone said hold and made me wait almost 20min on an international call never to get back to me. Their service on social media was just as bad and does not allow me to speak to a manager to complain about how I was misled. Considering taking legal action, will def get this to media to warn other customers.