I've just taken delivery of my new Anthracite City and I'm delighted with the leather and the colour, but there is a fold mark in the leather across the whole of the back of the bag. To me it's very noticeable and I'm unsure now what to do. Will the crease disappear with use? Or should I treat it with a care product? I'm reluctant to send it back, since I struggled to get a new one here in the UK. Most stores are now out of the anthracite City. I'd really appreciate any advice, if anyone has come across this problem before. Many thanks.