Nedbank is a *******

In january my bond was deducted on the 23 of december and again on the 1 of january,it was a hustle to get the money back till my child did not get the school of choice,i had to borrow money to cover up,now i check my bond statement i have been paying my bond of 470,000 since 2017 nedband tell me now ib 2025 thst my bond is now 455,000 .7 years i have bn paying never i missed anymonth if i miss it is reculculated and i pay areas separately.6,800 monthly since 2017 means nothing to nedbank . I wish i can cancel my bond if anyone knows what to do please help.