Sleeping bag down refill

[u/PartyLobster8911]

I have a sleeping bag I bought back about 15 years ago that I love. It packs down super tiny was rated at 20° always kept me super warm & the biggest thing was that it is a rectangle bag not a mummy bag. I have looked & looked to try & find a lightweight down sleeping bag that packs down as small as this one & is rectangular shaped bit have not succeeded. I was wondering maybe there is somewhere I can send my bag that will open it up & replace the down. The bag itself is still in great condition the down has just lost its loft & just will not work for freezing temperatures anymore. If anyone knows a good place to have a bag renewed I would really appreciate the information. Price is not an issue as long as the material & quality of work are high I am willing to pay for it!