i have a lg kp500 (lg cookie) and when ever i send a txt to like a 1900 number ( liket to get more games on my phone or enter comps on video hits) it dosnt let me i get a stupid message from optus saying i have incefficient credit when i have over $100 dollars P.S (i have a turbo cap, i put $30 i get $350 credit) but i dont think that has anything to do with it, someone please tell me how to fix, thx