Toronto to US package forwarding

In a bit of a pickle here! I'm in the UK and used a freight forwarding company to ship certificates to the US and Canada. What I usually do is send the company a box of certificates with the pre-paid USPS labels on them, and they take them out and ship them individually. Unfortunately, this time the whole box ended up in Canada and now the only solution they have for me is to have them picked up from the address in Toronto, brought back to the UK and then shipped back out to the US.

Is there any other way I can handle this? I'm wondering if there's some way to get it to a New York post office so they can be distributed from there? I've been in touch with companies like ReShip and Shipito, but sadly they can't assist.

Any advice would be greatly appreciated! Thanks in advance!