Data disappearing

Yesterday I received my monthly data allocation for my skylite package to my surprise when I woke up this morning I had 17kb of data , I checked my data before sleeping I had 13gig , to my surprise I woke up with 17kb and funny enough my night shift data is still sitting at 14.99gig data so clearly I didn’t have autoupadates as it would depleted my night shift bundle aswell, please kindly assist in refunding me my data as this is unacceptable, I clearly checked before going to bed that the was no active apps , I’ve been with Mtn for years and would hate to leave the network over something that can be resolved , I require the matter to be resolved urgently as I’m currently working from home