My contract months was extended (****mers)

Telkom administrators make a silly mistakes, I took a cellphone contract in 2022 August, it was a 24 months contract, it was supposed to end in August 2024, however I have noticed that according to their system my contract was extended with 3 more months, and I reported the matter with them because I was due for upgrade, they promised to rectify their mistakes, on my upgraded contract added those three months of which I have no clue where they got from. Telkom can be ****mers.You must be careful whenever taking contracts with them