5 Gigs anytime Data doing a vanishing act in less than a day

I purchased the wifi router and was advised that I would get 5 Gigs any time data as well 5 Gigs night, which totals 10 Gigs per month, however I have noticed now, that once I switch it on, I am barely on there for very long then I am advised my data has run out... How can it run out so quickly, not even 2 or so weeks let alone a day... I then logged a request to be contacted by Vodacom and for the umpteenth time I had to noticed how an agent will only try to call me once and not again thereafter... Also when I do answer the call no one ever answers and the call is dropped thereafter...

Please advise what is happening with my data... Clearly having it switched on for not even a few hours yet, can not allow so much data to magically disappear...

The last thing is how often I have had to advise the call centre consultant about my address and the online statements are still displaying the wrong address... My address is as follows and I will not be confirming this anymore so please once and for all fix the issue! 19 Selkirk Court Mirby Road Retreat Cape Town 7945