British Airways services are ridiculous

I booked a flight with British Airways to travel on the 11 th December 2020, to Cape Town. Unfortunately I could not travel due to the uncertainities COVID-19 poses. I called the call centre and they advised that I put my ticket on hold for later use and I did that. I thought they would send a voucher or something (like Kulula does) but they didnt. I always fly with Kulula, as a matter of fact, I saw the flight on the Kulula website but booked BA 'cause it was cheaper that day. My flight to Cape Town from Jhb was worth R857, so I wanted to use it as I'm planning to travel to Dbn soon and the return amount is +- R900 so I would just top up the difference. I called British Airways to assist with the booking and they won't allow me to use my own funds. They say I can only book a single trip because the flight ticket was put onhold, had it been a voucher, the request would have been successful. This does not make sense to me when your own consultant recommended that I put the ticket onhold and didn't even mention the two options available and the conditions attached to them thereof. Durban flights costs (return)are R898 so the difference between my Cape Town flight and the DBN flight trip would be R41.I was told I can only book a single flight(worth R449) which I asked them to in the meantime, and I was made to pay R90.

If I cannot book a return trip, can BA refund me because that is almost 50% of the total cost of the ticket that I am not willing to lose.

In addition to that, can customer service make sure to train consultants to state all the available options that BA has before they recommend.

I will await your response on the matter.