Tagg Digital - Order not delivered in time and now i have opted for cancellation not accepting the cancellation

I have ordered the product on *Dec **** they said it will be delivered by **Dec **** but hadn't received again said that it'll be received on **Dec **** ,but the product recieved on **Dec ****, mean while i have orders another product from another website ,although o tried to adjust the performance of the product was too worst being a smart watch it showing a heart beat for a wooden plank also , i have raised the request for cancellation ,it takes a huge and lengthy process when ever i call customer care it was saying all our executives were busy and reach u shorty i have mailed them no response , yesterday call has been connected they send me a form to cancell the product i have provided the same, today they were saying that we should courier the product, i have asked them after reaching the product of u don't refund the amount who is responsible then they were saying that cancellation not accepted it should be done in* days they hadn't gave me any details regarding cancelation now talking for rules ,then y dont they send the product in time