Telkom SA services

Really disappointed with telkom and their services . I awoke this morning with 700mbs in my phone , I haven’t been on the internet since and then I got told I have 300mbs left . I left my phone on charge and everything was gone . I called Telkom customer care service thrice and they said it could be the apps on my iPhone . They didn’t even care to investigate the matter or tell me where all my data had gone . Really disappointed.