Lenovo — I am complaining about lenovo A6000 smartphone

Address:

Solapur, Maharashtra, 413304

I have purchased this mobile last year due to advance feature of 4g which they have advertised. When I insert this sim in 4g slot, it is not showing any range but when I checked the sim in other mobile it is showing range. I contacted even customer care as well as service center of lenovo smartphone but they are not responding properly. They are saying it will not support 4g. Then why they have given that in feature as it will support 4g.