BILLED FOR INTERNET USAGE EVEN THOUGH INTERNET IS

My husband took out an internet contract cell *** . Varsity kids x 2 use the internet and ARE ALWAYS WITHIN MONTHLY USAGE LIMIT. We received notification in April that over 9 days R2.500 internet usage was utilised . The bill has now run up to R11k EVEN THOUGH MY LINE IS BLOCKED . Common sense says someone else is using my line . The ref nr for query logged at Menlyn was REQ ***. No one has responded . since ***5. As at ***5 my bill was at R7715.61 . We also wanted precise info as to what web sites were supposedly accessed . My children get free WI Fi usage at varsity AND NEVER DOWN LOKAD SERIES OR MOVIES off the mtn contact . Check my billing records since taking out the contract An urgent reply would be appreciated <br> My husband can be called on but he will probably refer you to my son Matteo