I will never advice anyone to take the contract with them

My cellphone upgrade was due on 13 May 2022,so i did an upgrade 31 May 2022 but surprisingly yesterday they debited R1479 56 when i call this morning they say it's pro rata and it's the first time i am paying so much for the R399 contract phone i am so dissaponted on MTN south Africa o won't renew my contract next time i will port to other network,and i got the call on the 7the that i will pay R506 but unfortunately they took my money trice