Zomato — I'm complaining about zomato credits

I've ordered on Zomato but I've received wrong product from zomato side. when i complained on zomato they refunded my money in the form of zomato credits with the deadline of only 24 hours but i didin't used it and they expired after 24 hours . when i complained it about it they said we will refund your amount within 24-72 hours but it about to over the time and i didn't receive my money they are giving the same mail again and again.