Regarding an order no 1468723250

This is regarding an order no 1468723250 which i placed through paytm on 15th January. First of all after the dispatch,i didnt receive any cashback.i mailed customer care,for which they replied that i dint apply for a cashback which is not true.then i though may be it is true and i asked them to cancell my order straight away,they have cancelled it and mailed me that in case i get it ,i should not recieve it,i did the same and returned it to the post man.Next day,i got a message that ur order has been delivered.i was shocked and mailed them again, and again cancelled it through their site,then they say to send it back,how should i send it when i have already returned it to the postman.Since that time i am mailing and tried to contact these guys but they only reply with a mail tht they will get back to me in next 48-72 hrs but it has been so many days and they have not come out with a solution,and i have not got my money back to the wallet.i am so surprised with such a pathetic service they provide and give no value to people’s money and valuable time.