bad service

My account is handled by the lady called Anita . I have send a proof of payment to her email and sms she told me she didnot received it her excuse she is working from home she is using a wifi but i also sms the proof of payment . and is not the first time , I ask her for the breakdown the amount she said i owe it was around about may/june she said the same thing offline she is working from home wifi issues never heard from her . Today again she never got proof payment and i also email it to myself i received it , i am also at home and i am also using wifi .