My Stanley Thermos Leaking from Lid. Unresponsive Warranty Service

I purchased a Stanley thermos and utilized it for approximately 5 months before encountering an issue with leakage from the lid. I reached out to Stanley's lifetime warranty service, and they assured me that they would get back to me. However, it has been a month now and I still haven't received any further communication from them. I completed another form in hopes of receiving a response, but unfortunately, I have yet to hear back. I used to really enjoy using this thermos, but unfortunately, the problem with leaking has rendered it completely useless. I purchased it with the intention of using it during the summer, but now that the season has arrived, the thermos remains untouched and idle at home. What actions should I take? I require a prompt resolution.