Is their immutable backup provider?

Currently I am using a BlueRay device to have a immutable backup of my server. Each week after a back up I take a disk and put it in a vault.

This is a bit cumbersom process and also I like to have a real time backup.

I am looking for online service that can provide the same type of service. The only way some one can erase the backup is by not paying the bills.

Having access to online erase function is not acceptable as one of the eployees can go postal and erase the content.

Thoughts ?