Bank charges

Is this legal the amount of Bank fees and interest First National bank takes.

I have a small business that I am running for the last 5 years with First National Bank every month its the same story the money comes in from the 1st to the 7th and every month I ask for an overdraft to cover me and they decline me

I have 4 declined payments and the money came in the same day it was declined this is how much I was charged its shocking Aspire ***.00 Gold Business ***.00 Total amount: R1 1154 just in two days

Then the bank charges to have these accounts Gold Business Account R299.00 Aspire: R39 Total: R338

Grand Total of R1 492.00 the bank has made out of a small business

Then I made a loan of R7000.00 in November to cover expenses. The interest was from R380.81 The total amount of interest paid was R2 357.09

The amount I owe still is R1000.00 but it climbs daily with interest

Is this legal that a bank can take so much money from you in interest fees and is the other banks that does the same. They don't call back they don't correspond and no matter how you try to resolve the issue you land up in more debt so how can a small business survive with exhoberhant fees like these