No sms notifications

Ever since i have upgraded my savings account to savy plus i have not being receiving sms notifications for all my transactions. I have called in to the call centre many times but they always have excuses like its my network, or the message was not generated. They tell me they have to deactivate and reactivate it , but each time i still have the same problem. Went into the gateway branch, the consultant said she doesn't know why that happens. Its important that i know mybalance every time i swipe or withdraw, otherwise what is the point of having the sms notification service? Getting no help from nedbank, very disappointing!