Tenacious Tape is an excellent product. You can get a similar product by gore tex.
http://www.gore-tex.co.uk/blog/do-it-yourself-gore-tex-jacket-repairs/I've seen one of the outdoor shops giving out little strips of Tenacious Tape, just snipping a bit of the roll and handing it out to folk who have damaged their jacket.
jmarkb wrote:Scottish Mountain Gear in Musselburgh will do this for you, and you can post stuff to them: <span class="skimlinks-unlinked">https://www.scottishmountaingear.com/repair-service</span>
If your crampons are quite new, they may be much sharper than necessary and it may be worth taking a file to the points and blunting them off a little.
A lot of gear that the high street send back to manufacturers for repairs end up at this place getting fixed.
So potentially an item gets sent from a shop here in Scotland to Germany for inspection then sent to Scotland for repair then back to Germany to be sent back to the shop in Scotland for the customer