Vodafone India — Tariff changed illegally

For the Vodafone number [protected] (Kolkata)

I requested to change my tariff to Red4Business 349 with Rs. 50 discount in email, but Vodafone has changed my tariff without the discount. Now either give me Rs. 50 discount or give me back my previous tariff SEP 14 N CUG as per the reference numbers [protected], [protected] and also check my last bills . See the attachment email details, what I asked in email and what is done.
Last correspondence of that interaction was [protected].