Henry harvin Education - Certificate denied due to false payment pending claim

I had enrolled in a course at Henry Harvin in ****, for PG program in Content writing. The total course fee was ***** INR and my husband made the payment in * instalments. The first amount towards the loan was completely paid on **th May ****. There was a small payment done in the beginning to book the seat and the remaining amount had to be paid by **th May ****. This was around ****INR. We made the payment on **th May **** itself. For the next * months, we completed the rest of the payment. After the course and the exam, I started applying for certificates. My requests were denied stating that there was a pending amount of **** INR. When I replied to them that I already made the payment, they requested to submit the proof. Even though I submitted the proof, none of the executives confirmed the receipt and my certificate requests kept on getting denied. There were few executives who even confirmed that the payment was received following which I reapplied for certificates. But still, the same issue was being stated. Worst of all, their legal team even sent a demand notice to make the payment. The latest communication with an executive was on **th July **** where the executive confirmed the payment was received. He asked to wait for * hours for confirmation before applying for certificates. I did not receive any confirmation. My Henry Harvin membership also expired on **th July **** following which I am unable to apply for certificates as they are demanding more money to extend my membership. I paid the full amount of *****INR, even shared the no dues certificate and the only thing I am left with is a demand notice. Please help me to either get a full refund or certificate.