British school of language - Online course payment is not refunded

I wanted to take a english course online, so I paid *,***/- rs for it on *st of May ****. I took first class on *rd May **** and realised that the service is really bad. I asked them to switch me to a course of personal trainer with * month validity costing ****/- rs and they refused. Then I requested them to give me the refund, they denied it, stating it can't be done. I have repeatedly asked them to refund my amount they are denying it.

Company course page: https://www.britishschooloflanguages.com/best-online-english-speaking-course-india
Company policy page: https://www.britishschooloflanguages.com/refund-and-cancellation-policy
Mode of contact: Whatsapp
Date of payment: *st May ****
Date of attending the first class: *rd May ****
Date of raising the issue: *th May ****