Kia Connect Invoice

I’m wondering how many other people are struggling to pay an invoice. Back in February I charged with Kia Connect App. I received an invoice and when they attempted to pay it with the credit card on the system, ( despite being ok on the initial setup fee ) it was declined. The reason apparently was that Kia Connect had changed their details slightly. I re entered my credit card details again, but still nothing worked. I started getting emails and letters threatening to disconnect account etc. I made numerous calls to Kia Connect, who suggested it was a widespread problem, reactivated my acccount. I tried a different credit card, still no joy. You are not able to settle the bill by phone, online or via app. The only way appears to be via a German bank. Today my account has been deactivated again. I tried to phone them, lines busy and unable to get through,it puts phone down ( where as always managed to get through easily). I’m just trying to gauge how many others are also affected.