To the best of my knowledge the only place to get repairs like this done is to return it to Ping themselves (via a proshop). I believe they do not supply 'spares' to anybody.
I lost some the weights out of my I series irons and they insisted they did the repairs despite it being a very simple job of gluing in new ones.
Thanks Jim,
I contacted Ping and they say there is no option to replace the insert as it’s an integral part of the assembly process to install it. Very annoying. I don’t want to fork out for a new putter
Thanks for your help though,
Martin.