Redmi note 8 pro - Replaced new phone not delivered yet

Dear Sir/Madam,

I purchased a phone redmi note * pro on *nd June from Hotmail tezpur. The phone turned out defective at home. The same was informed to the store, they directed us to mi service center Tezpur. They gave us the certificate that it would be replaced within * days. Accordingly the previous phone was submitted.
After * days i.e **/** the ekart delivery guy called from Guwahati and told us that the service center has entered the wrong pin number and hence it cannot be delivered to tezpur. We contacted service center, they told they would ask someone to pick the phone from guwahati and it would be brought to tezpur on **/** and accordingly we will get the phone. The same was informed to mi call center, they assured that we would get the phone on Saturday or the money would be refunded.
But on friday service center called and told the phone couldnt be delivered on saturday instead it would be deliverd on Monday. We were fine. Again they called on Sunday i.e yesterday and told the phone will be delivered on thursday. This is not acceptable. We are facing this harrassment because of service center's mistake. We called mi call center yesterday but they didn't give good response.
Now I dont have the phone and the money is also gone.