I just rang telecom because I received some unsolicited texts from what seem like a premium text service. I am not going to reply to it but I rang telecom and apparently there is no way to block, or preferably white-list, premium services being able to add charges to my telecom account.

Basically I would like to allow TXT-a-park and no others to add charges to my account.

Last year I had to help a relative who was being charged for premium text services and it was a real pain to get them to stop and to recover the money charged.