PHONE 5 MONTHS OLD NOT WORKING

I bough a contract phone from digital planet but through letsatsi I've logged several calls with that useless organisation no one has called me back up until today he phone is not even a year now they phone is not working so I can send it back as there is no insurance on the phone and even my contract sim card has never been replaced I so regret buying the phone from them as now Samsung cant even repair the phone I'm so furious <br> my reff they gave me numbers<br> Lett10340<br> how do I go about this matter now please assist