Not receiving Contractual data bundles on top up

I've been trying to have this matter resolved for the past 2 months now. Firstly, my top up date was changes without notice, then last month i did not get the data bundle linked to my package. i tried calling but it's almost impossible to get through to your call center or my line gets disconnected or when i do i am told a request is logged with some department. same thing has happened again this month. Please fix this! i am now owed 2 months' worth of data.