20 GB data depleted in 4 days

Took out a data contract in December. 20GB anytime and20GB night owl. Used the data with no issues December and Jan with Surplus at the end of the month. On the 1st Feb I get the new data loaded of which is depleted by the 4th of Feb. How is that even possible. I have done nothing different from the previous 2 months and to top it all was at a family function on Saturday and Sunday. Which means from the 1st - 04th I probably used 4 hours of data in totality. To top it off when checking data usage on the app it shows that my data for March is also depleted.

Please can someone look into this as a matter of urgency. Data cell number ***