The Art of Non -Service Service

I booked and paid for a full service flight on SAA And after a flight delay in Cape Town was without any explanation by the ground staff ushered onto a Mango No Frills flight instead. The air hostess told they would get me to my destination just as well..... the point is I paid for a full service flight and you took my money and did not deliver. I wrote to you on your facebook page and sent you my flight details.... it has been weeks and still you have not rep****. What you did was ********* and I want my money back, ir at least a replacement full service flight like the one intended but not received.