British Airways complaint: Cannot reach British Airways to change my ticket

I booked to fly to Lagos on 22 August and return to London on 1st Sept 2021. Due to unforeseen family situation in Nigeria I need to change my return date to 1st October 2021.

I went online to BA.com to Manage My Booking and did the required procedure. I chose the date and it took me through the procedure and showed I have to receive a refund of £384.80. I tried to finalise the procedure and it said I should contact BA through 0344 493 0787. I dialled this number and stayed on line fore more than 30 minutes. When I felt frustrated i dropped off.

The following day, Saturday, 14821 I tried again and eventually I got through to a lady to whom I explained the situation. She said I should give her 4-5 minutes for her to check the cost to change the date for the flight. About 4mins later to phone went dead.

I suspected that BA does not want to refund what the online procedure stated to be refunded to me.

I then went back into the system and started all over again but this time I chose a date where I would have to pay additional amount of £47 and this time the process went through.

Now instead of obtaining a refund I am manipulated to pay £4 for a date which is not entirely convenient for me.