Left with additional costs just to maintain a warranty that means nothing

In January 2020 I bought a 2018 Nissan Micra, first registered in November 2018. The car came with a 5 year/ 150 000 km factory warranty and 3 year/ 45 000 km service plan. During hard lock down I was an essential worker meaning that I drove my car every day. One morning before work, the car wouldn't start. My dad took the battery to Naskar, as Nissan simply was not available to assist at all (other brands such as Mazda made sure they have the AA on standby). Naskar initially told us the battery just needs a good charge. Then, almost 2 weeks ago, I was about to leave the office, when again my car wouldn't start. My insurance had to send someone to jump start the car. We were advised to test the alternator, as a battery usually lasts longer than 5 years (this battery isn't even 2 years old). The next morning we took the car to Nissan Silverton, whom advised that the battery needs to be replaced, but they can't assist as the vehicle has no warranty. After a lot of frustration we eventually found out that the vehicle received its first 2 services at Nissan Bloemfontein, the dealership didn't even bother to load the services on Avis and did not stamp the booklet. No Nissan is willing to stamp the book, so for the rest of the vehicle's warranty period, it will always be a fight, if there is a warranty issue, to get it fixed. We were also told that we must buy a battery through Nissan SA, if the service record can be traced, as this will affect the vehicle's warranty if we buy another battery through another supplier. We took the vehicle to Nissan Hatfield, who was able to track the service history of the vehicle and also service the vehicle (all in all we received fantastic service from the service advisor), but the branch did not have any batteries. It's been a week of promises, but still no battery . My sister contacted several other Nissan branches, whom advised that they have never purchased batteries through Nissan SA, but rather through places like Battery Centre. Despite logging a complaint with Nissan SA (Vanecia Ndhlovana ***), Nissan SA has refused to assist me, only threatened my sister (whom logged the complaint) that my warranty would be void if I buy another battery. I requested a loan unit, but was told it's "subject to availability" and no-one bothered to check if one is available. Instead of dealing with the problem, they have now gone and made the complaint about Nissan Hatfield. I now have to incur costs of borrowing another vehicle, because my "new vehicle" can't be used. Nissan's warranty, cheap parts and service isn't even worth the time and effort, I will never buy a Nissan again.