Michelin Airstop A1

Michelin inner tubes - I've never been a fan of specific tubes, I just get the cheapest at the time and make do.  I got some of these Michelin Airstop A1 tubes, thinking a little bit more usually results in a better tube.  Wrong!  Maybe I got a faulty batch but on pumping one up to around 90PSI is exploded in the early hours waking me up.  I checked the following morning to see a rupture tear on the inside of the tube, not near the tyre wall or running surface but on the valve side.  I checked the rim of the wheel, fine, no splinters, visible spokes; I checked for debris in the tyre itself, nothing - clean.

I assumed it was just a faulty one, didn't worry about it and put in the other one.  Following day, about 12 hours after putting it in, not riding it at all, BANG!  The replacement pops too!  Same type of tear, different area, an outwards tear in the tube wall.

Is there any point contacting Michelin?  I doubt it, probably get no-where and the shop I bought them from (Geoff Smiths Cycle in Bolton) wouldn't replace them, and can't blame them to be honest.  Back to Decathlon and eBay for all my cycling needs.