garmin mount keeps breaking

[expatmanxman]

Has anyone else had problems with the securing pins breaking on a garmin zumo mount. Twice in the last 6 months I've had one of the pins that go into the back of the unit body snap. Both times it happened while the unit was mounted in the cradle, one left pin and one right so not even the same pin each time. When I emailed Garmin and told them this was turning into an expensive exercise they sent me another mount free as a goodwill gesture which makes me wonder if this is a common problem. I'm reluctant to mount the unit until I've sorted out what's going wrong, the mounts are too dear to just keep buying new ones. An alternative might be to buy a non functioning Zumo and swap the back but I don't know if that's feasible.
Any ideas???