Debt Collection Harassment

An account I had with ABSA was handed over to Hammond Pole Attorneys. On 7 February 2020, I received a settlement offer with a discount. I accepted the settlement and made the payment on 13 February 2020. Since then I have been contacted numerous times to settle the account. Every time, I forwarded the settlement confirmation. But I am still being contacted! I have even been contacted by the same person that offered me the settlement in the first place! I am at my wits end with this company.