HP India — printer cartridge that comes with printer only has 50% ink

I purchased hp deskjet ink advantage 2135 on 12.08.2017. Along with printer a black and color cartridge is given. The black ink cartridge stopped working on 15th september 2018, so i took it to volta technology solutions - hp authorised service centre (Parthasarathi puram, t nagar, chennai, tamil nadu 600017). Service center says the cartridge is empty and that the cartridge given along with printer is usually only filled up to 50% and not full and sold to customers. When i check the ink levels in the hp software it shows 50% ink is still available.