***** at bank

Morning,, I write this with utmost shock with my experience with Fnb Mall. Of north polokwane. I came in the morning today to withdraw R100k and upon my request, I was sent from pillar to post and I was told I needed to make an appointment but still they can help me. This took about 20 minutes the the teller constantly going out of her teller cubicle(u could see she's making calls). Finnally the monies were given to me and I walked straight to my car,, after driving off from the mall,, 600m later I am being followed by white BMW that kept on turning in my back as I turned,, I then went off to another mall,, the same BMW parked next to me. And I reversed,, the two occupants went back inside and a chase ensued as I sped off,, I literally went into a red traffic light so I can lose these guys,, I drove as fast I could.into the nearest town (tzaneen)) until they lost me.. Question is,,, how did this guys know I have cash? Could the delay at the bank be the reason I am being chased? This left me very scared and demotivate to even step my foot in that bank..