Daily maximum API calls reached

Thank you for your response, i checked my profile and i saw that what you said is correct, there are 500 api calls so i reached the limit. The question came to me because i only talked to the bot 250 times through the api, but today I've been doing some tests and i saw that every time i call the api, the total number of api calls increases by two, not just one, It seems that when I've been talking to the bot, I didn't pass the conversation id to the api in the second and subsequent messages, so every time i write a new line, the bot creates a new conversation (now i'm passing the conversation id and the total api calls increment by one on every response).
So now i want to ask if this reasoning is correct: every time a new user starts a conversation there are two api calls (one to create the conversation and one to respond), then, when the conversation has started and there are a conversation id, the api calls increment by one in every response. Is that correct?

I have zero api call after a series of test. And told me to upgrade. What must i do?