Morris garages - My car not delivered since 4 weeks from service station

I hve lodged a complaint to MG dealer service station for the problem which i was having in my new MG Hector car. The car went for second service at that time i hve lodged the complaint for a noise which was coming out from the machine when the car starts first time in the morning. They confirmed that yes it is coming & when delivered to me they said it is resolved. Again after * days the same noise started & i complaint for the same. They again took the car at service station by saying some unethical reasons. When they delivered the car back to me again they confirmed that it is now resolved.
After * days the same machine noise started & again they took the car for inspection. The car is lying at service station * weeks from now & again they are confirming that everything is fine as per their parameters. So i hve asked them to give me in writing that if the same problem persist within short pwriod of span than wht action will be taken by you?????? If any than pls mention the type of action in the email. But they are nt giving me in writing the thing i want & always states that ur car is ready for delivery bt i am nt taking ad they are nt giving me in writing.

So i want the help from Voxya.com on hw to proceed further in this case as i m right at my part as i doubt that there is a mojor issue in the car machine which they might hve rectified bt not accepting as they are nt ready to give in writing.
The car purchased date is **.**.**** & from Mar **th lock down started for * months & than after restriction on going out of house, city & state.so the car didnt run the actual KM which it has to be i.e. appx **K uptill now from the date of purchase instead it ran only *K KM till date & has lot of complaint.

Need you expert advise & support to action further.