Manager cannot control staff

I just came from SA Post office in SASOLBURG branch 46 fichardt stress. Went to pick up a parcel and was helped by a rude lady called Thandiwe Sokoto. I went to get my parcel at about 11:15 then she went to the back and looked for it but couldn't find it as she said there are too many parcel to go through and it's a mess ,so she said I must came back later she will go look for it and call me once she find it. So since she didn't call I decided to go back before they close. I went back at 14:45 and she said she forgot. She went and looked again and quickly came back and said I must come back again as she can't find it and the lady working in that department is on lunch. That when I told her she can't send me back again couse it will be the 3rd time coming back and it cost me petrol and time to come back again and the branch is closing soon. She said I must come back tomorrow or wait for the lady that on lunch couse there's nothing she can do as she does not work sorting parcels. I went stood outside and lucky I saw the manager ( white thin lady) i explain her my story and she told me to come back as she will get my parcel for me which she did( thanks). I went back to the same teller to collect parcel and that's wen she started acting very rude screaming to the manager saying I was almost in tears just for a parcel , what must she do if she can't find the parcel. I ask her what she means by me being in tears for a parcel as if I'm not gonna get it. She raise her voice at me and yes why are you crying for a parcel ,here manager is there listen,the banking hall if full and because she's so rude even the poor manager can't control her. This kind of behavior at work is unacceptable, I'm not happy at all about the treatment I got from that lady. And if the manager cannot control her staff then we have a problem at that branch.