Bad service on a Sunday!

I had tried to check in online for a flight on Sunday at 6:45. A notice was then received that check in was unavailable because of site maintenance I assumed. I tried again later and was able to pre seat myself therefore I thought invasion done with check in. I then got to the airport at 6:10 which was fine I thought, but I was told that i was late, and met by a lady with Sunday blues at guest services after requesting for the manager she said that the manager would tell me the same thing. I insisted and then the manager was brought in, as the service agent was wanting to charge R990 to book another flight, the manager even said this was too much and reduced it to R550. How can they make a technical fault on their side the customers problem? Even more is that I emailed them the same day and have not received feedback to date! Despicable!