Interest can only be exempted if the repayment is made in full before the final repayment date. If you don't repay in full, you will have to charge interest for new consumption.

The rule of interest collection is: charge five ten thousandths of interest from the date of consumption until it is paid off.

For example:

7. 10 Consumption 5000

7.30 (the final repayment date in July) or 100.

8.30 (the last repayment date in August) or 100.

.....

From 7. 10, 5000 will receive 7.30 with interest of 0.0005, then 8.30 with interest of 0.0005 according to 4900, and then 4800. . . . And so on until it is paid off.

By the way, the interest generated does not charge interest, not compound interest.