NEVER CAN GET THROUGH TO THE CALL CENTER

I called last week to request for increase on my RCS card. Almost a week later and still no response, i keep sending call me backs (online) chatting to the BOT which always says there is no human available! Called countless times but never can get a hold of the call center! After 20mins of holding i cut the call! Its impossible to get a hold of you guys for anything! You either need to upgrade your online system so we can apply for an increase / decrease online and get approved there and then or get more staff at your call center! this is terrible service.