I want my C11 to be attended to STILL UNDER WARRANTY

C11 Prepaid cellphone always gives me problem with a notification PHONE VALIDATION AND WARRANTY SERVICE I took it to Vodacom branch at Protea Glen Mall I was told I don't buy enough Airtime and Data and.they didn't or failed to assist Why is there no customer service They are not professional Not the first time experience I want my phone attended and the Shop must be Closed Down with immediate effect as they are failing the whole community that needs assistance everyone complaining about their service