Changed booking times day before my flight via SMS

Booked and paid for flight on Monday to go to Durban on friday the 1 Oct 2021 at 4.10pm. Got an sms this morning saying the delayed my flight for for 2,5 hours later 6.25pm. I tried to call them on to try change the booking for earlier time. No one answers the phone, I called 4 different occasions and waited over 30min and still get no agent answers the call. This isnt the first time this has happened. Never again will i EVER USE BRITISH AIRWAYS OR KALULA.