Acc Paid but always disconnected

Every time i have to call multi choice to connect my services...as soon as i make payment at shoprite i email receipt to ********** and a few days later im disconnected. Now my acc as occured charges up to R400 for reconnection when ever i have to call in and ask why its been disconnected. I paid on the 15th of dec and i wake up today its disconnected. I have never received such bad service like this.