Dell India — Issue not resolved with Dell Inspiron 7586

I have submitted my Dell laptop - Service Tag - BXDV5P2 (out of warranty) with Dell Authorised Center - Raghav Computers situated in Ramphal Chowk Palam Dwarka via - Service request number - 1835. The error was - when switch on the laptop only Dell logo appears. They took out the SSD card and gave it to me since Dell do not take responsibility of data. After some days, the team informed me there is no major issue in the laptop, issue was with the SSD. So I bought the new WD SSD and gave it to them for install the windows and fixing the issue. After the installation of windows 10 2004 version, they gave me the laptop. They said you can also download the latest Windows 21H1 version. When I came back home and started to install the antivirus I realised - there is some problem with my keyboard when I was pressing H - the result was H6. Then to resolve this issue I downloaded the latest Windows - 21H1 and fortunately the issue got resolved. Then next day a another issue started - frequent disconnect of WIFI, so I went to the Dell site and updated the WIFI drivers and it got fixed for the time being. In the evening the same frequent disconnect of WIFI, then next day in the afternoon reached the Dell Authorised Center. The technician did the same thing which I did, downloaded and installed the drivers from Dell site, it got fixed. After 3 or 4 days later again started with same issue since in my office new project got started so not able to get the time to visit the authorised center. So for temporary fixed - factory setting of wireless connection in BIOS and it worked for some days but soon the similar situation. Today I called up the authorised center, initially they provide some online checks through AnyDesk but could not fixed the issue, now they are saying they need to install the older version of Windows for which they are asking to pay again since 7 days has been lapsed since I took the delivery of my laptop.
Please suggest if I need to pay them again ? If yes - please specify the reason since the WIFI issue was not resolved only the temporary fix and there was no issue prior to submitting the laptop.