HDFC Bank — Cancellation of One Assist Membership

Last year when availed HDFC credit card, got an offer that if purchase for over specific amount for 3 months, the card can be made lifetime free. But I missed to purchase. On the next day, got a call saying they are from bank and as I missed to reach that amount, if I pay Rs.1899 the credit card can be made lifetime free. I said yes and got a confirmation mail in the name of OneAssist. I got debited that amount from my account. But this year also(19/03/2021), my credit card got a bill of Rs.1899. Tried mailing to OneAssist and also calling, but no benefit. Please help me to cancel this asap.

OneAssist Relationship Number : 10315287