The domain was suspended from DNS because you hadn't paid your renewal bill. The "strange page" was put up by your registrar to notify any visitors of this and to direct them towards their billing system. The idea is to effectively shame people into paying their bills in a timely manner. Your registrar would've sent you at least three different emails before and shortly after the domain's expiration including a notice of what would happen if you didn't pay on time. If you didn't receive these, then that's on you for not keeping your contact details up to date and correct, which you're required to under your registration contract, and which is why you get those emails out periodically asking that you verify that the details they have for you are correct.
If you don't pay your phone bills, electricity bills, rent, &c. on time, you'd expect the service to be removed. Why would domain names be any different?
The domain was suspended from DNS because you hadn't paid your renewal bill. The "strange page" was put up by your registrar to notify any visitors of this and to direct them towards their billing system. The idea is to effectively shame people into paying their bills in a timely manner. Your registrar would've sent you at least three different emails before and shortly after the domain's expiration including a notice of what would happen if you didn't pay on time. If you didn't receive these, then that's on you for not keeping your contact details up to date and correct, which you're required to under your registration contract, and which is why you get those emails out periodically asking that you verify that the details they have for you are correct.
If you don't pay your phone bills, electricity bills, rent, &c. on time, you'd expect the service to be removed. Why would domain names be any different?