I have an S10 that the band has broken . Seem a bit flimsy Where can I get a replacement wrist band?

I was looking for a new wrist band under warranty. Contacting Garmin is almost impossible. They certainly put up as many barriers as possible. 

That link I included above in my response will take you to the support site  for your watch, the bottom of the page contains the the call & chat boxes for you to select to view the office hours, and the phone number for our office in your region. 

Anything inquiries regarding your warranty would require give Garmin Support a call, and they will be able to discuss any questions you may have regarding options for your the band on your watch.                                                                                           

on my 4th replacement band for the S10. on this basis alone, i would not recommend a garmin product - it is a proprietary band, a poor design, slow shipping and completely maddening to have to keep buying bands from Garmin.

There are also 3rd party options available for purchase through sites like Amazon that are compatible with the Approach S10 as well if a different material is desired.