Anyone else had a problem with next sleeping bags? I've had two now where the stitching has come apart, even after a few washes. They are really poor quality despite being expensive so just wondering if others have found the same? I've put in a complaint to next but they don't seem interested in the safety aspect and just told me to return in store (but don't have my receipt so can't). I've also got other sleeping bags from supermarket brands that were worn all winter and they are as good as new!