Be Careful and double check invoice booking

After booking flights on Travelstart we choose to take 2 bags @ R150 each. Seen it is 40kg it will be more than enough for 4 people. Arriving at Cape Town we had no problem booking in our bags. Wanting to come back from OR Tambo - the sh@t hit the fan. They could not locate any booking for our bags. Travelstart was phoned and not even they could pick up any booking for our bags. I asked how this is possible as we had no problems at Cape Town? I was greeted with silence and a \oh ok\". We did not wanted to miss our flights and was forced to pay the extra for the bags. On both sides of me were different people complaining about the exact same problem. And all had to pay extra. After arriving i started phoning Travelstart and send emails. They informed me we did not book this and our bags were taken in as hand luggage. They keep on referring me back to the invoice - the invoice only shows extras, admin fees ext. I am posting this so people will be careful and insist on a more detailed invoice. This seems to me is a very easy way of making extra cash as passengers are forced to pay this extra for the bags or miss their flights. In the future i will ask for a more detailed invoice."