My bank reversed a chargeback in the merchant's favour. Can I force card scheme arbitration?

Generally, no: you can't force arbitration. Chargeback rules are a private arrangement between the card network, your bank and the merchant's bank. You're not a party to them, arbitration costs the bank money, and the RBI Ombudsman won't order a bank to file it.

What you can do:

1. Ask the bank, in writing and quickly, to file pre-arbitration. The windows are short (days to weeks). Give the reasons the merchant's rebuttal is wrong and attach any evidence you didn't send before. Banks sometimes agree when the case is strong and well documented.
2. Check the reason code and the merchant's evidence. For services, "not provided" and "not as described" are different grounds. If the merchant produced a signed agreement whose terms cover what happened, the chargeback may genuinely fail on the merits.
3. Use the RBI Ombudsman narrowly, for service failures by the bank (it didn't tell you the reason for the reversal, missed timelines, or ignored your evidence), not to order arbitration.
4. Take the merchant to the District Consumer Commission. This is usually the right forum for the underlying dispute. It's free for claims up to ₹5 lakh, and you can file where you live, so the merchant has to respond in your city.

The chargeback and the consumer complaint aren't either-or. Pursue the merchant directly while the bank route plays out.