Microsoft who took over Nokia's mobile division, is no longer offering renewals for MixRadio in India. The subscription allowed users to download songs. Mixradio will continue as a streaming only service.
The related FAQ page on microsoft.com has the following message:
"You will no-longer be able to purchase renewals for your unlimited download subscription via Operator Billing, Credit/Debit Card or Voucher as this feature is no-longer available"
wmpoweruser.com received a reply from Mixradio India's twitter handle saying they are working on re-enabling vouchers.