unknown part by iphone

On 23/02/2024 I took my iPhone for battery replacement it was at 73%. They replace the battery only to realise they used **** battery. Now i have a message on my phone which states that part is non genuine or not functioning as expected or the installation is incomplete. I return the charger and the phone on the 26/02/2024 since its heating when charging. They refuse to give me back my money even though i have the receipt and when i ask for my old battery back they say they threw it away.