Data "******"

I have a contract (since 2020) - 50 GB ANYTIME 50 GB NIGHT SURFER THIS EQUALS 100 GB PER MONTH I would like to know why – on the 1st day of most months – data of approx. 10+GB has been “used” with absolutely no usage from midnight to early morning when I check my balance (which should show 100 GB AVAILABLE). 11,56GB was "taken" one second after midnight 1st June 2022??? How? I always have at least 50GB over at the end of each month. It seems like “someone” is “*****ing” my data and this is happening over and over again. Been into the Telkom shop (Eastgate) several times - no one can give me an answer as to why I never receive my 100GB data each month ??? I'm pretty sure that no one will contact me regarding this!