One Plus - Earbuds return and replacement fruad

I have purchased one plus earbuds z and before purchasing I have called their rep that if I don't like the product then can I get that return and one of their rep told me that yes you can return it and get the refund on your bank account. After the product got delivered I call to customer care and they told me that never say that we will return your product if previous rep said so then we are sorry for that and we cant do nothing. After that I have filed a complaint online in consumer helpline ***** but once they call me with the same resolution that they cant return the product.