Changing money

We were about out of pesos in our personal cash today, so I made a trip to Urdaneta this morning. The first money-changer I went to cashed $300, but she wouldn’t accept the other two $100 bills. She said something about not having those serial numbers yet. I went to another money changer, and she took my money and told me to have a seat. After she finished with another customer, she called me back to the counter and told me she didn’t have any cash and that I should go back to the other money-changer. I tried a money-changer in the mall, and she also told me she had no cash.