Refusal to repair my tablet

I bought a Sumsang tabet on 24 August 201. On July 2014 it ahad a screen and I took it for repairs. It had the same problem and I took it for repairs on 20 Jene 2015. Samsung is refusing to repair citing warranty expired. The warranty expired while it was with them. It has been three months and I haven't received my tablet. Every time I inquire am told a different story. First it was rhey didnt have the partshense the delays, then the receipt was not clear and I submitted a reprint. Its very disappointing that a brand like this treat one of its loyal customers like this. I want Samsung to take responsibility and repair my tablet as it was still under warranty when I took it for repairs, the warranty expired while the tablet was with them.