The cost of humble pie just went up

Being unworldly and/or stupid I have been known to make mistakes. My latest seems to relate to postage in the UK. I thought I'd grasped the new system (based on size as well as weight) but clearly I've goofed in at least some cases. So anyone having to pay any excess postage should deduct it from their next subscription, assuming they want to renew. So much for the Royal Mail website, with its claim that 2nd Class Large is 'suitable for most magazines'. Ah, well...