Can cops lie about tickets?

So i was speeding and got caught. But the cop told me right before i was leaving that he was just going to give me a warning. Then he handed me this pink paper and walked away quickly. when i opened it , it had a fine and i had already left. i dont know if they give out papers for warnings. also on the paper where it says "make cheque or money order payable to the minister of finance. do not send cash through the mail. Voluntary payment is considered a guilty plea" and next to that paragraph it looks like hey put a squiggly bracket next to it with the word no next to it. what does this mean and can i do anything at all to fight it?