Mike,
Im Glad that you got a response, but to say that this was an inconvenience is somewhat of an understatement. The tyres have clearly failed. I too replaced all four tyres with Continentals as I also refused point blank to have Dunlops fitted & for an extra £10 its worth it for the safety factor and piece of mind.
Simon, did you manage to get your issue resolved with Dunlop ? due to the fact my tyres were disposed of I had no way of supporting my claim... lesson learned.
bottom line is that I am happy that this issue has been highlighted and that others have been checked and had the defective tyres replaced with a superior alternative.
Anyway... I have now taken delivery of a new A7 55 TFSI with Pirelli P zero's 😉 still 275 30 21.... hopefully there are no issues with these!