Billing problem

I'm having a rather serious problem as I am no longer receiving any invoices from SDL (although money is being withdrawn) and I cannot get in touch with the support as all links invariably lead to the community. I also would like to cancel my subscription but cannot find any way to do that. This is all quite infuriating. Does anybody have any advice to give? Surely SDL must have some responsibility towards their users to handle a problem like this? Or am I supposed to purchase a support agreement in order to be allowed to a) get my invoices for my accounts and b) cancel my subscription?