Data depleted but still have data

I received a notification that my internet data has been depleted, and email as well as an SMS. When logging onto the MWEB portal the page also shows that my data bundle has been depleted however when tallying the data I used for the month, I still have 40GB left of my 200GB bundle. This has happened before and when I received this alert I loaded another data bundle and an hour later the site showed that it was also depleted, loaded another one and also showed depleted. Luckily I didn't purchase a new bundle for this month. Fix your website to display accurate and true information and don't con people into buying additional bundles just to make extra money out of them. They didn't even want to refund me the prices for the two bundles that I bought in error because of their website being inaccurate.