How to tell your parents something?

Ok, so I have a prepaid phone and there was 100 dollars on it the beginning of September, which was supposed to last until at least March or April. I decided to have a texting spree and it landed me at 60 dollars after two weeks, my dad was so angry he said if I kept it up my phone would be taken away. Now its almost the end of October and I only have 3 cents left! Should I either come straightforward to my very strict dad and offer to do whatever it takes to pay it off and have my phone taken away, or wait until he finds out? What would you do? Please help and serious answers!