Next time you get a package from UPS just don't answer the door.
1) Call/Email UPS and request a commercial invoice and the depot the parcel is being held at. If it's not being held at a depot tell them you want to self-clear and for them to hold it. You may have to argue with them for a while to convince them this is a possibility.
2) Go to a CBSA office with the original receipt, commercial invoice and depot location, and pay taxes to get your B15 form. You shouldn't pay taxes on shipping.
3) Call UPS and ask them where you can send the B15 form.
4) Send them the B15 form with your tracking number on it and ask them to release your package.