FNB just does not get back to me

I was debited twice on 4 OCTOBER 2020 already for petrol that I put in and it went off my debit card once and off my credit card once aswell for the same petrol.

1st attempt with dibit card was "declined" but received no slip for it.

2nd attempt I gave my credit card instead and the transaction went through.

2 days later I saw the transaction went through on both my cards.

I disputed this multiple times. FNB replies that I need decline slip... I do not have it as the petrol attendant did not give anything to me...

I lodged complaints at FNB and they say they will get back to me within 48 HRS... They don't ever get back to me...

What a disgrace to FNB... how can you treat your customers like this???

Shame on you!!