harassment with phone calls

I have an account with Foshini. I am in arrears with R100 . Foshini staff are calling me every single day ********** 274/ ********** 00/ ********** 287 monday to saturday 18h00 at night 20H58 at night, 3 to 4 times day. I have spoken to a lady yesterday nellie stampler ********** 280 at 15:08 and advise her that month end is only on thursday, I know i need to pay again but if you are going to phone me from the 1 of the month untill the 31 of each month 3-4 times a day then i would like to know if i am the only person owing Foshini. She was very arrogant about it. The same afternoon i got a call again 15h11 and 18h00 from ********** 000, which i need not answer.This morning 09h45 i got again a call from ********** from rene about payment again. Series, She is reading the notes but still phone to confirm payment again. Is this not harassment?