why is a person blocking me from going inside the 8th gym in pokemon pearl?

[Bob]

Alright I just got palkia in mt.coronet and I went to sunyshore and i see a peron in the alipe four.He tell's me to give the gym leader a hot battel because he gets sucky battels and calls me hotshot.So i go to the gym and he says sorry hotshot the gym leader isn't there so i walk around and see a waterfall so i need hm waterfall but some girl back there says i need sunyshore badge to get hm waterfall PLZ help someone