McDonald's hard burger

Very disappointed in McDonald's Somerset West. I bought a Cajun meal and the patty of the Cajun was extremely hard that I couldn't even chew it. The lady behind the counter Mamat was very rude and said I'm wasting her time as she has alot of people in the drive thru and can't still deal with a unhappy customer. I then requested the manager who was polite and replaced the burger immediately no hassles. I believe that it's very important to have people skills when working with customers. Something this lady Mamat lacks.