Byju's — wrongful product delivery & irresponsible behavior

I booked class 10, 11 & 12th study material with 10’ lenovo calling tab on rs 75000/- in nov’18 and paid 10% @ rs 7500/- as advance. Sales executive – mr. Sanchit-tnl21819143 has committed that they will guide the student regularly & visit at home to take care of the performance of child on monthly basis etc. To get the order.
First of all, i received my order after passing almost a month whereas they have committed 7 days for delivery. I have booked 10’ tab but i received 7’ used tab around 1 year old on cdma technology (Which is not applicable presently). Battery backup is also not good. I have lodged complain to customer care same day. They have committed to resolve the issue asap but they were just passing 15 days refund policy timeline by given different kind of excuses smartly.
After passing 15 days, they had changed their statement. Neither they are replacing product nor responding on the mails. Beside that nobody visited at my home till yet to check the performance of the child as already 4 month passed. Sales executive-mr. Sanchit is also not picking the phones. His 10th exam also completed without using byjus course. This is totally wastage of money.
Now, customer executive/mentor clearly refused the call/complain received during 15 days of product received. Either they have manipulate the call records or trying to misguide us whereas i have call record in my call history.
The accent of the tutorial is also in south-malayalam language which is not easily understandable to my child.
They are following up for their installment only not for your problems. They are cheating to the people smartly. Once you passed 15 days refund policy period, you will be responsible for any type of problem either related to product hardware/software or child performance. Byjus will not support any thing beside that to commit false statement & recover his dues. This is totally wastage of money. Poor backend support. Not recommend at all.
If my problem is not resolved within 7 days, i will again put the complaint on same portal to show the seriousness of the byjus on the customer pain.