Product: Credit card or prepaid card

After receiving continued charges from subscriptions that were already terminated, I first fully paid my Apple Card payment of $ XXXX on XX/XX/22 and locked my card. 
Then in the following weeks, I noticed extra charges again in addition to Apple Card interest so out of frustration and my last resort, I called customer service, paid the additional balance of $ XXXX in full and closed my account. I explicitly asked the representative that whether this includes all the charges on my account and that I will no longer receive anymore fees and the representative confirmed. 
I have many other credit cards that I have properly managed in the past 9 years without a single missed payment, but the Apple Card 's horrible customer service and lack of transparency on details of charges and their inability to discontinue or dispute charges led me to closing the account. 
However, on XX/XX/22, I noticed my credit score was dropped and the close-up details showed a missed payment from Apple Card. To my surprise, I checked the details and despite showing that my account is closed, it entailed an unexplained $ XXXX interest. 
With raging frustration, I called the customer service the same day, inquired about this interest charge that made no sense after closing an account and since the representative had no idea and didn't know why I was charged, told me that I will receive a call back from her supervisor. 
On XX/XX/22, I received a missed call from them, with a voicemail to call back again. So I called the next morning ( on XX/XX/22 ), expecting to be talking to actual specialists. 
I presented my case clearly at the beginning of the call and asked to be routed to the final escalation as I need 1 ) explanation of this interest that makes no sense when an account is closed and one expects to have nothing to do with that card/deal anymore 2 ) answer as to why my account and data was still recorded after account deletion - this to me is a data privacy leakage and even if it's not considered to be legally, I wanted an explicit way to remove all my data as I wish to longer run into unexpected issues with this irresponsible creditor. 3 ) A remediation on my credit score and whether this late payment can be un-done as it has caused damage to my credit card. 
Despite my explicit query up-front, I was held on call for 50 minutes, just to be told that the person was a new hire, and didn't know what could be done. ( and unclear answer as to maybe this could be a trailing interest ) I asked why I can't be transferred to the supervisor, and the representative said that she can't transfer me. I was suggested that I needed to call back and ask to talk to the supervisor but somehow she did not suggest me that in the beginning and wasted my time. But I suspect dishonesty from the representative or the supervisor in the background who refused to connect. ( because she at some point mentioned that the supervisor asked whether she can waive the interest and she was not about to do that on her system ) In my 9 years of being a credit user, this has been the worst experience I've had in all aspects of their card from transparency at data level, to customer service. 
Every time I've called, the representatives has no idea and bounced me back and forth without any explicit solution. 
The card has no email or official means for communication besides their useless phone number and no dedicated department for complaints, disputes or cases such as this. 
Hence, my complaint is not about the small $ XXXX charge. It's not about the money, it's about the many standards that have been broken and the damage caused to my credit score. I have no idea if this can be undone and remediated from the card 's side but I was in a critical period of needing my score to be stable and good and Apple card has caused me damage twice : first by me having to close my card and second due to this charge post closing my account.