Difficult to get hold of

This month I experienced all 4 tyre pressure sensors giving up one after the other - just as the warranty expired.

I tried calling Ford SA but no one answered. I emailed them, but no response to my email.

The dealership doing the repair says that filling Nitrogen caused the problem. My research suggests otherwise and Nitrogen in my previous vehicles for more than 5 years never caused an issue with the sensors. I think this is a manufacturing fault and needs to be resolved by Ford - if only I could get hold of them to discuss it.