Disgusting service received from call centre staff

I called to book for my vacation club yesterday morning, spoke to Mbali who for some reason couldn't book because we have two units with the same membership number. Found it very strange as I've been booking all these years with no issues, she promised to call back the same day but of course she didn't. She had said that the week I was looking for is available and she will get it sorted. I called today spoke to Sihilfwe(not sure of the spelling) who put me on hold for about 20 minutes for absolutely nothing and was told the week I wanted was booked. I am so furious at the incomptency of your staff members and I am not pleased that the week I wanted is not there anymore when I had called on time, it is not fair at all. Funny that this Sihiflwe could book but Mbali couldn't. I want you to listen to my conversation with Mbali yesterday and provide me with feedback as to why she did not book or bother to call me back as promised. This is ridiculous for a company like yourself to treat customers the way she did. I am disgusted at the service I received