Planetspark — Regarding cancellation of registration and refund of amount

I enrolled my son Abhiraj Parkhi with planetspark and statrted classes with Date of first class: 15.05.2023. During the payment counseling session, they have told that firm five classes are observation classes and u can discontinue the classes i[censored] want to. After attending three classes, online class is not seen effective for my son so we requested to cancel the registration and refund the amount. Also raised ticket to cancel my EMI payment but still no response. Please help