Mobile Phone Xchange not only offer some of the best cash deals for old or unwanted mobile phones but they have consistently offered some great shopping voucher alternatives, always offering a higher value than cash. To top this off, Mobile Phone Xchange have now added Marks & Spencer vouchers to their mobile phone buying options.  So, if you’re an avid M&S shopper, you can get more money for your mobile phone in the form of M&S gift vouchers – nice!