Unhappy

Our flight was on the 17 April 2025 at 05:45, we left home at 04:30 on the way we were trying to check in on line but was not allowing us to check in and I tried calling the *** with no success it says they start working at 07:00 we got to ye airport at 05:05 and we were told that we are late for check in the check in that closes at 05:05 ? and we are late how? When we trying explaining that we have been trusting to get hold of them ans check in online we were told that once they open check in at the airport the online one closes my question is where is that information communicated to us? And getting at the airport at 05:30 for a 05:45 flight is it being late? We had to pay an extra R600 for all this