Stanley Refuses to Replace My Lifetime Warranty Thermoses and Only Offers a Refund

They want me to return my Stanley thermoses, one purchased a year ago and the other six months ago, both sold under the so-called lifetime warranty, citing a manufacturing defect in the email they sent today. This is absurd and only serves to inconvenience the customer. I have no issue with the product being replaced, but requesting the product back just to issue a refund is illogical. If there’s a problem, replace it with a new one. How am I supposed to buy a new thermos with the refunded amount? Moreover, one of the thermoses was a gift—am I supposed to ask for it back just to receive a refund? Stand by your promise and resolve this by replacing the products sold with a lifetime warranty, instead of creating unnecessary inconvenience for your customers.