billing enquiry... not coming back to me

accounts department... my account is R696...but my contract is R 369... i have paid that amount via debit order of R369... then why is my account R696. account number ********** 53.. i have acquired from the billing department... twice... if you are going to double bill me then i am going to be really upset...refrence numbers: ********** 6 & ********** 9... please fix this issue ASAP thanks..