Horrible Call Centre Experience

I've just had the most horrible and disrespectful call with one of your call centre agents: Wendy Mphaphuli (I think that is how it is spelled?)

I have never in my life been helped by a customer services representative who blatantly LAUGHED while the call was in progress. I asked he what was so funny and she **** and insisted it was not her, but it was background noise. We continued the call and she had the audacity to LAUGH once again! I asked her to connect me to a supervisor but apparently no one was available. How do you run a call-centre with no supervisor available?

She was not able to advise on the query I had either. By that time I was too annoyed to try and have more patience and get the issue resolved or find the right answers. Hopefully, when I call back tomorrow, someone who is professional enough with the requisite competence would be able to assist me.