not satsfied

I Have a concern about the lady,working at the kiosk that i dont i understand,how she operate on the tills.In most cases i like to buy my lunch in that shop,and pay at the kiosk.On a particular day i bought a plastic and she tilled it as a bath towel luckily i checked my slips ,nd i saw a bath towel tilled wch i ddnt even buy,so he called the till operator to cancel the towel tilled and after a week i went to the same kiosk and pay for my lunch the same lady assisted me, a bought a plastic and she tilled it twice,i also checked my slips and i told her,that she tilled the plastic twice,this got me to raise eyebrows if the same situations is not happenning to other customers,lightning cannot strike in the same place twice.Why everytime when she assiting me the same problem has to arise/