In my current situation, what advice could one give with regards to studies that could lead to a career in investment banking?

Hi

So I am currently seeking advice with regards to subject/degree choice with regards to a career in investment banking.

Currently I am a 3rd year Geology major at Rhodes university in South Africa. I had my doubts about my career choice from day 1, but decided to just go on through it. After 6 weeks of work experience at acacia gold mine in Tanzania and a few weeks of various work experience across mines in South Africa, I have decided it is not a field of work that I wish to pursue. I plan to just complete my undergrad degree and apply for a BCOM degree elsewhere. Might perhaps seek bursary opportunities, some advice with regards to this would be appreciated.

I have done a fair amount of research with regards to investment banking. Prop trading, somewhat interests me. I have thought of applying for a BCOM acc degree at the university of Cape Town, WITS is also an option. Just not entirely sure what other subject choices would be be beneficial? Finance, Economics, Maths?

I know this would be sometime in the future, but I would like to perhaps write the CFA exam once I had finished my undergrad. I just wish to plan ahead, with regards to my subject choice in order to best prepare me for these exams.

Any general advice would be much appreciated.