Due to polymer shortages (covid related) we are making a component change to our rubber compound. This requires an SCR (supplier change request) from out customer. We have done everything correctly and above board. The change needs to be made to keep the supply chain full. Our customer is not acknowledging the SCR and we need to make the choice to shut down the customer down or ship parts and a PPAP to them (despite the fact that they have ignored the SCR). We are talking about supplying to Tier 1/2 automotive supplier. Any thoughts on this? How would IATF see this?