Coach wants me to pay twice

(I do not know if that post shell be here if not I'm sorry but I really need help)

I’m 16 and I’ve been training with a coach for a couple of weeks. My dad says he already paid the coach in cash at the beginning of February, but now the coach is saying the “time expired” and I need to pay again. There’s no receipt because it was cash and the coach didn’t record it. I can’t just leave the gym because my dad doesn’t want the money to be wasted, and he also wants me to handle this with the coach myself so I don’t look like a pushover. Also, because of Ramadan, I won’t be training for a while, but my dad still wants me to come back after Ramadan to finish all the sessions and make sure the money is used. I don’t want to get into a fight (My coach is scruge and my dad has problems with anger), but I also don't want to pay twice. How would you deal with this situation? Whats shell I do?