unfair business practice

Ordered a cellphone last week which i still had to send the bank statement to verify my account and on Friday i decided when they called me I am no longer taking the phone and the consultant dropped the call on my ear. Yesterday 17 August they delivered and by then was expecting deliveries from Shein and Temu respectively so I opened the parcel and it was someting i dont want so now on cancellation they say I must pay R2900 cancellation which is ridiculous and unreasonables so i said they can pick the parcel and will fight tooth and nail for this unfair business practice. They lure clients with false pretense and when you change your nind within the 5 days they said is free then all of a sudden must pay and those finer details where never explained to me.