Retail giant - appalling service

I opened an account recently with Truworths. I made 2 payments during December 2022 which does not seem to appear on my statement. Subsequently I have been inundated with SMS, EMAILS, PHONE CALLS regarding an OVERDUE account and INTEREST CHARGES. Every second call or sms I receive is from Truworths.

I phoned them yesterday,was informed to send a PROOF OF PAYMENT. I did that today the next call and first call I receive is from Truworths Credit Dept complaining about an overdue amount on my account and when can they expect payment. My balance outstanding should R40 plus after deduction of payments.