I have been using Woolworths Credit card for morethan 7years now

I have been using Woolworths Credit card for morethan 7years now.On the 03 March 2023 i paid my account through cellphone banking So when i notice no message of paid account,i went to Woolworths Westgate and they call financial department. They needed proof..i gave them proof. My case has not been resolved till today. They keep saying after 4 days but now is 8 days since i reported and my case is not solved. Instead they put lot of interest and i pay my account very well. The mistake is theirs. Please i need help..