was i wrong in this situation?

i have a money order that was mailed to me. we went to a grocery store to cash it and the employee said “i’m sorry we don’t cash postal money orders here, we only cash money orders from *store name*.” my dad responded with “on google, it says you do. why can’t you just do it?” and she says “sorry sir, that’s our policy. i’m not sure why it says that.” and he was visibly frustrated and said “but why?” and she said “i’m not sure but i can get you a manager.” he said “no, whatever.” and started to walk away, but he then walked back and said “i don’t get why on google it says you cash them but you don’t.” she again asks if he would like to speak to a manager and he said “no, whatever, f*ck that you guys suck”. after he said this i tapped his arm and told him to stop, i was anxious and just wanted to de-escalate the situation. we get outside of the store and he says “don’t you ever do that to me again. don’t defy your parent for some stranger. what makes you think that’s okay to hit me infront of someone?” (i didn’t hit him, i tapped him). i apologized for what i did and said i shouldn’t have done it. he said “i don’t want to hear that, i want to know what made you think it was okay to act like that”. now he’s not speaking to me. i just want to know if i was being out of line for what i did.