Very bad service from Pick n pay Eyethu mall

Yesterday around 14:00,i went to Pick n pay at Eyethu to purchase groceries worth a R1000, when I got to the till, i adviced the lady that I was going to pay using my gift /incentive that I received from Huawei since I work for a telecommunications service provider, i advised the lady refused to help as well as her supervisor Monica, I then call the manager Helen who gave me very bad attitude and told me she's aware of the card but won't help me because my card doesn't look legit the manager also suspected me of ***** although I gave her my original ID and the Huawei service number so she can call and verify who i am, she still refused, and even told me I can report this if I want to she doesn't care. I recieved very bad service I was very unhappy with The manager (Helen's) treatment and attitude towards me. What upsets me even was the fact that I always paid using the same card at the same branch and other pick n pay outlets who didn't give me a problem.