BOOKING ISSUES - UNRESOLVED AND NOT PROFESSIONAL

I've been online with Travelstart 15th July - yesterday - a couple of hours. They messed up my flights from Rio to South Africa. I'm travelling with my family with a child and they have seriously inconvenience us with the connecting flights. We held on for hours on the calls yesterday. Told someone will call us back 3 - 4 times but no return calls. The last call I made I refused to wait for someone to call me back. The agent then book us a new flight for 2 days later - we had to now make our own accommodation and transport. They assist with nothing - next thing they lines was off ( We have different time zones) - on the last call the agent confirm we have new flight tickets. Today a day later, we are trying to check in - again, there is no tickets. We are holding on line for hours today - we've spent 2 days now to resolve this with them - NO RESOLVE