Loan Complaint payment break

I had a loan payment break from May to July, They charged me interest which I was never told about when in branch and calling them I’m being sent from pillar to post. No one can answer on why I’m being charged this ridiculous interest. Worst of all I am told i can claim interest back after few consecutive payment (Fine by me) however interest being refunded is not same as my current loan balance that should be as per letter received and balance on their systems too.i am taking this matter further should I not get resolved by today. Responsibility must be taken. Sat at branch for a little over 2hours for such a small Query.