Does anyone know how to fix the Huawei M735 full memory problem?

Hi, I just got this phone about 11 days ago. I moved all of my ringtones, songs and pictures to my sd memory card and deleted all of my sent and received text and media messages, my contacts as well as my apps. It still says the memory is full and that my inbox is full. Hence I can't receive text messages though I constantly receive alerts. Can someone shed some light on this? I'm thinking of taking it back to get another one or should I just get a different phone entirely? Is the M750 any better?