This is a well known issue when your payment transaction could not be processed. To be honest, I would like to buy a subscription as well as many others in here, and I would like to offer a solution. I read on the internet about a good credit card payment system, and probably this the best way to fix this issue with the payment system on this site. Payment gateway UK could be easily integrated, they are helping with that, and they are using the API or Python templates to do that, so there will not be any issue with integration. More than that they do not have payment failures at all. I think this is the best way to fix this issue