rubbish refund

Spent about £240 on 2 kurio tablets for my children for christmas.obviously the children used them but we found out they are absolutely rubbish.you can not transfer apps onto memory card so they only keep about 3 games on then we have to wipe it all to get new ones!! I have all my packaging and reciepts and smyths have said unless the tablets have a fault that they will test for i can not have a refund.the product is not what i expected and does not perform as expected unhappy children but i cant have a refund.i used to love smyths.not any more.