Tikka freaks - Wrong item given and wrong coupon code info given

I placed an order for butter chicken and got a different order and the pieces were burnt and boneless for which I was given a redemption coupon of ***.I have been trying to use d coupon from last one mth but it showed not eligible for this user .I contacted d support team they said they can c tht the coupon has not been used and I can paste it and again o was not able to order as the restaurant was closed till the time they resolved my issue and then the support person told me tht it is valid till **th April and can simply use it and next time it will certainly apply again I tried some days later but same thing happened and again the executive took good ** to ** minutes and said the same thing and said tht there is an error but it is not used and is valid till **th and again d restaurant gt closed.Yesterday again I tried placing an order again the same error was there n no body helped and today mrg one support executive is telling me tht I have already used the coupon and he is telling me on *th April for an order of *** rs .My point is y was it nt told before to me and why I was harassed so many times and ended up ordering nothing as restaurant closed and how come other executives told me tht my coupon is not used and is valid and then why wud I use a coupon of *** for an amount of *** rs