Byjus aaksh institution - Money not refunding

I had purchased akash byjus online course for class **-** PCM. I was promised by the councellor that I will get an EMI of **months. The course cost ***k in which **k was paid as down payment and rest was as emi which was of **months but I denied councellor said me that he will increase tenure to **months. I get the course on ** November and during that time I had examination in my school. So I didn't study for days but when I study I was not satisfied I want cancellation and I said councellor about that but he said that it will be cancelled by some days. There are some more information which I have to say but in personal level not in online portal.