Payments made for swtor need to be based on the country of origin, given china is banned , you shouldnt even of been able to play without a VPN , and if your card was based in a different country other then china it would of been refused based on you being located in china.
If you attempted to get around the geo blocks via different methods this may be what they are calling multiple payment issues.
Calling CS may not be assistance to you to the best of my knowledge as per this link
Since the studio or Terms of Service are the only teams handling these actions, customer service is unable to override them or help with appeals.
You can call CS on the phone however it isn't usually something they can deal with, so they may direct it back to the TOS team anyways, and where it comes to account disputes that email address is the funnel.
If they determined you are physically located in china at the time they reviewed this as they can determine IP locations on account access, it likely would not of helped.
I can only suggest emailing back and politely request further clarification on what has occurred.
They do not place a ban on an account for no justification
Hope you get clarification on what occurred
the only thing i will will mention is EA tend to not like chargebacks , there is the possibility that initiating a chargeback will flow to the EA / Origin account being banned.
So if possible I would leave that as a very last resort
