Thank you for letting us know about this question that you have in mind.
Apologies if this situation has to bother you. We would like to let you know that Trend Micro serial numbers supports a completely independent subscription. That's why the remaining days from your previous subscription was not continued when you activated the new one.
Anyway, we have already transferred the remaining days from your old serial number to the new one. We will highly appreciate it if you can confirm the said transfer.
We'd love to hear from you soon! Should you have any other concern please do not hesitate to reach out to us.