Exactly the same thing happened to one of my mirrors when I had a DL1000 - it was under warranty but took Suzuki 3 months in the end to replace it.
In the mean time I had gone out and purchased a set of after market mirrors which are far superior - imho - both in quality and view.
When I sold the Strom I kept them - if you are interested in buying them then pm me.
![smiley_shrug :shrug:](https://www.v-strom.co.uk/smf/Smileys/default/smiley_shrug.gif)