Actually, this is the time to be tough.

Please try what I suggested and DON'T feed him for a few days. The way you are doing it now, he knows it is available pretty much all day every day so there is no rush to try this "new" weird food.

Do not put food in for a few days.

Also, how large is the reptomin compared to the frog? If too big you should be breaking the sticks or using the smaller ones.

Don't let the food sit there all day. Feed when you are around to monitor then take it out after 15 min or so of him not eating.

I have had to deal with many stubborn frogs and this has always worked for me - - fast a few days, try feeding a small amount, if he doesn't eat then fast a few more days and repeat. These frogs can go a few weeks with out food so 4 days is not really worrying yet.

If you give in now and offer him a ton of stuff again, you are going to have a harder time getting him to eat the sticks later.