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We have seen similar situations and the only fix that will not damage the door shelf is to thaw out the frozen roast. This will take time and patience.
We would remove all items from the shelves. Take some hot water and soak rags in the hot water. Then you will have to put the rags on the roast and rotate them with more rags until you thawed enough of the roast to remove it. You can also use a hair dryer to speed up the process.
Let me know if you would like more information or clarification.