Hi RV4LES,
You entered that tournament when you still in the Pro Tier. Since you entered as a Pro you remain to compete in that tier for the duration of the event, even if you earn a promotion in the middle of the event. Since you entered the Pro Tier of the event, you are restricted from using Master Tier clubs so you don't get an unfair club advantage. If you wish to continue posting scores in that event, you'll need to go back to your Pro Tier club setup.
Any future tournaments that you enter from here on out (and any normal rounds you play) will have you competing in the Master Tier and you will be able to use all of your clubs.