Rude agents and undue harassment.

Truworths call centre agents as well as their SMS service are harassing my mother referencing unpaid monthly instalments. Payments have been made in store on a monthly basis at the instalment amount (and sometimes more). We have record of this and so does the Truworths store in Metlife Mall, King William's Town. Can Truworths do a proper recon of their accounts and payments and leave my mother alone. The call centre are very rude and are lacking in manners over phonecalls.