Travelstart Ignoring Clients Request to Cancel flight bookings

My flight booking is for Monday 20th December 2021 @18H45, Been trying to cancel my return flight booking with travelstart since Thursday(16thDec21) evening, made use of their whatsapp services and website to do so. Guess what?! It's Saturday(18thDec21) morning and I am still waiting for their response. This is definitely the last time I am making use of their services. Their agents are clearly ignoring my requests.