Wow Momo Foods Pvt Ltd — I am complaining about Refused to Redeem Voucher

Address:

Breach Candy, Bhulabhai Desai Road, Mumbai - 400026

I have received a Wow momos voucher with a discount 20% on the amount of Rs.300 or above order on take away or dine in through book my show.
When I asked to Redeem the voucher while billing, the Branch person refused to give a discount at Wow Momos outlet at Breach Candy, Bhulabhai Desai Road, Mumbai - 400026. I'd recommend you to check your system before you release any vouchers. Why is this does not happen? Why are you not giving pre-information/intimation to your branch person about the new offers? This is unacceptable. Request you to please redeem my 20% amount from the bill of Rs. 397/- (Bill No. - MUM[protected] and Cashier ID - MUM05202. Awaiting your prompt reply.