UNFAIR!!!!!!

I had my item due on the 12th of May 2023 and called in on the 13th to find about the status , an employee called Gift at Cash Con China Mall said i could still pay for extension, he advised of the amount and that it must be paid to their account immediately. I did that . Monday i called to find out if they updated this; i was told about an additional 633 that i have to pay. Like??? They didn't even pick up my calls this was via an audio on whatsapp . I was given excuses about the pop being sent Sunday, them not controlling the system . No acknowledging that their internal stuff erred . Escalated the matter to head office and they just said go back to the store that not been willing to help me . A WHOLE ****!!!!