Bad Service I Need my Refund

On the 30th of December booked a flight from ORTambo jon=hannesburg to Richardsbay checked in at the counter boojed my lugged in and boarding time was 10:30 only to be the at 1035 and i was told the boarding gate was closed as i was in the waiting lounge and the it was mentioned that i missed my flight which was at 11:15 when i inquired at the help desk i was given attitude by the two ladies working there had to wait close to 2 hours for my lugage that was checked back don't even know why and what happened and i was told i must pay for another flight and want to complain i want my refund as i did not get to use the ticket to their flight which they claim i missed..Bad Service and attitude after paying so much money for a single flight to Richards bay am so angry and will never use nor recommend the airline to anyone and i need clarity and my refund from Airlink **** service