Where is my Windows 10 software

My HP laptop had a problem so I contacted the HP international help desk. The support Tech (Andrei Kovacs) remotely took over my machine and diagnosed a hardware problem. As my laptop is still under warrantee I was advised to take it to Ensure Services for repair. Ensure Services is the recommended and only authorized repair agent in South Africa for HP, so I took my laptop to them for repair. Later a technician from Ensure phoned me and I was informed that the keyboard had been replaced but the problem still existed and could he have permission to reinstall Windows 10, which I gave as I felt he is an expert. Then I was informed that the mother board had been replaced and I could now collect my machine. I asked the technician if Windows was as up to date as it was when they received it and he assured me it was. When I got home I checked my laptop and much to my dismay I found that instead of the installation being to the original spec of the hard disc being partitioned with Win 10 NTFS operating system on one side of the partition and the Win 10 installation software on the other. The hard disc had been formatted and Win 10 FAT operating system is installed. Further checks revealed that windows is not up to date. I phoned Ensure and was referred to the technician who denied having reinstalled Windows as it was not on the job card. I then spoke to the service supervisor who checked the job card and repeated what the technician had said, he also checked with the technician with the same result. After much discussion he said to take the laptop in and they would TRY to reinstall Windows as original spec but he would phone me back. No call back was received. I then called HP international and spoke to Andrei Kovacs and asked for assistance. He phoned me back and informed me that a Manager from Ensure would phone me. No phone calls from Ensure have been made to me. This leaves me with the problem that, for whatever reason, should I need to reinstall Windows I can’t because I no longer have the software and no the installation key. This leaved me to speculate if the installation of windows on my laptop is actually legal. Further Ensure only have businesses in Mid Rand, Durban and Cape Town so if you live in the Free State as I do a journey to their offices to see IF they can reinstall Windows is not viable especially as it would involve two trips.