Sam's Club – manager shouted racist remarks over contaminated rice

I went to Sam`s today (1/29/25 around 9:30)to get customer service. I tried to talk to the manager. He said he was the manager and asked me why I was doing this and he was very rude.( The manager`s name is Dotti)
I showed him the rice I took because the foreign substance was so disgusting( this is the second time it was found in the rice. The first time my husband threw it away, but it was so strange that the same substance came out again so I showed him the story and he made me feel racist by raising his voice so much that. I felt insulted because he didn`t understand English. He asked me what nationality meant. I was so shocked and felt miserable. How can someone like this be the manager of such a big company?
I am also disappointed in Sam`s.
Please send me your opinion on how you will handle my complaint.