Has anyone else had problems with Geox trainers? My 4 yr old boy loves his red trainers and has had them for under 2 months. This last week we've noticed that the back of the trainers have worn away so much that you can see the air hole inside the heel! We noticed this straight after a trip to the park when the 4yr old had enjoyed a good time on the slide - that is the only way the heel could have worn away. We've returned them to the shop who say we have to wait to hear from the sales rep but says it is unlikely that they will give a refund - where does it say that a child shouldn't play on a slide wearing trainers?! Surely they're not fit for purpose? Has anyone else had a similar problem?