First thing I'd do is contact the card issuer to see if they actually did reject it or whether the problem lies with the card clearer and it never reached the bank.

Most banks do reject a small percentage of payments automatically as part of their 'fraud prevention', I myself have experienced this three times over the last 10 years, twice they were recurring subscriptions that had run for years but that made no difference, the 'system' just rejected them intentionally so I was forced to call he bank; two different banks in these three events.