NEED HELP.

My Motorola edge 60 fusion phone which i got October last year, randomly froze and blacked out. So i took it the service center and they told me that the motherboard has an issue and they'll repair it as it came under warranty, i gave it to them and they said it'll take max 10 days.
[I'm a college student and i can't imagine working without my phone] They gave me spare phone, which only works when put on a charger.

Fast forward after 10 days, I called them to ask if its fixed, but the repairer told it'll take another ten days cause the part hasn't come from the warehouse (The city where i live in is pretty small and the warehouse is in the capital). Today, marks the 12th day and still no updates from the service center.

Its really frustrating to me as the spare phone isn't working as well, and they keep delaying it again and again.
I mailed Motorola, sent a complaint as well but no replies whatsoever.
What should I practically do? Cause I don't think they're taking it seriously.