Banks change money, but slightly better exchange rates can be had at money changers. The rate is usually lower than in Manila, but is surely not unreasonable. All major currencies can be changed, so there is no reason to stop for one night in Manila to change your money.
Credit Cards. Better resorts and hotels accept credit cards, but since there are no facilities to withdraw cash since there are no credit card companies on the island, you will be charged a surcharge for the usage of these cards. Do not blame the resorts for this surcharge. They are under no obligation to accept credit cards - it is a service provided for the user - and they also, like you, will have to make the trip to Batangas to collect your payment.
Shopping. You will quickly discover that most establishments do not carry sufficient cash. Often you will be asked to wait while a staff member runs out of the store with your money, leaving you wondering if you will ever see them back as time passes. No worry, they will return with your changed PHP 100.00, they only had to move to other shops next door till the required result is reached. It would be unreasonable to feel offended. This is nothing personal: it is only business. If you would like to avoid this practice or hurry things along, be sure to carry plenty of smaller bill (PHP 10.00, PHP 20.00, and PHP 50.00) instead of "all this big money". Carrying coins may prove to be quite helpful as well.
Tip: "Losing face" is never pleasant, but in Asia - this includes the Philippines - it is really a sensitive matter. Customers getting upset, because they have to wait or because they are being asked to provide a certain combination of coins or smaller bills, will come eventually to the conclusion that voicing out a strong opinion is not speeding up the process at all. Being prepared with your change is the best solution.
There are some supermarkets that are prepared to provide smaller bills. Banks are not really jumping to the idea and you might be required to fall in line.