Instacart complaint: Hidden service fees and overcharged

I have been a member with Instacart for a year or so and pay A monthly service fee of $9.99 a month. With every order that I have placed I was unaware that I was being charged an extra service fee amount. I called customer service and live chat with a representative. He told me that I should’ve filed a complaint to receive a refund. I told him I just learned about this fee by the instacart representative I was live chatting with. He refused to resolve this problem and wouldn’t refund me all of these service fee cost. The customer service rep claims that the automated system added those fees by mistake. It’s hundreds of dollars I was overcharged. The customer service rep offered me a $5.00 credit. This has not been resolved nor would the rep allow me to speak with a supervisor. He continued to refuse to transfer me tjj oh speak to a supervisor. He then willingly stopped communicating with me knowing that the live chat would expire after a few minutes by not responding.