Suspicious activities on credit card

I've tried contacting FNB via a contact form on their website and by emailing *** but have not received any response.

In November 2019 I got a new credit card and my balance was transferred from the old one. On 1 December 2019 my accounting app shows that I was over R1 million in debt despite me not asking to increase my credit limit at all. On 31 December, R639,868.00 was transferred into my account. On 31 January 2020, another R425,779.20 was transferred into my account. This seems somewhat suspicious.

I am happy to provide any other details necessary.