no service at all and maponya branch is worse

i went to maponya mall to upgrade , they told me to cancel the contract as i want to get a data contract , i cancelled and in 30 days time i was gonna go and apply for a new data contract .. after few days the call centre called me to say why i am cancelling the contract i told them they said that they can upgrade on their side but someone will contact me , i got i missed call from them and try to contact the sales call centre they will contact me and i decided to go to maponya mall to get help they seem less interested to my complaint and they dont wanna help , the problem is i am getting billed for nothing without having a device or phone ..my contract ended along time ago ....can somebody help me to get a tab 4..10.1 samsung ...its all that i need ......