What i have in my mind is that in case you have few swipers on page/app, then mySwiper var can return an array instead of swiper instance. Try to console.log(mySwiper) to see what is there. If there is an array, then use more specific selector when you init Swiper, e.g.:
var swiperEl = Dom7(page.container).find('.swiper-container')[0];
var mySwiper=new Swiper(swiperEl, {
...
};