snapdeal not paying refund

On 7th october 2018, i purchased ankur boxer shorts from snapdeal, order Id: 23928558510, the material received was very inferior quality, snapdeal asked me to return the material and promised me refund after receipt of the material , when they were silent after weeks, i mail them to enquire about my refund money ,they said they dont have my bank account details , i again mailed them with my bank ac details,they said they will immediately process, but now they are completely silent and not responding to any of calls.