I canceled my device subscription. Why have I received an e-mail saying that my HMD Mobile data plan will be canceled as well?

Upon canceling your device subscription, you received a termination notice, as per section 4.4 of the HMD Mobile services contract. Your HMD Mobile plan will be valid until the end of the current billing cycle. If you want to port-out your HMD Mobile phone number, you should do so immediately.