Infrastructure Development Finance Company [IDFC] — Idfc infra bonds tranche 2 - non receipt of refund

Holding 4 nos IDFC INFRA BONDS TRENCH 2. folio no IDB0149982. I had received refund cheque no 012198 for Rs 21604/- dtd 22.2.2021 but remained undeposited by me. I had sent original cheque for refund and one more cheq no 009195 for Rs 1600/- dtd 21/2/2019 pertaining to yearly interest., (both cheqs remained undeposited by me though oversight, and were sent in original along with covering letter) to Kfintech, Hyderabad on 28/6/21 which were received by them on 3rd july 2021. cheques were sent through Professional Couriers. following up since 12/10/2021. On 12th November, as per their mail I had sent copies of my PAN and copy of cancelled cheque. yet no refund received to my account . On follow up, repeated reply to "send the PAN and cheque copy." is sent to me. I would also like to have a phone number other than call center where i can speak to right person.