Ever since they changed it from $2 a day to $3 a day some times I can't send SMS it says the SMS isn't available on my plan I is just a normal text to my daughter but I have unlimited text and calls and data
Right, so when you text do you get an error message?
From what device to what device?
Did you use you have an iPhone but now dont?
Have you spoken to Optus tech support about your inability to text?