Poor post purchase response

I have normally received good service from Travelcheck (past years ago) but am extremely frustrated at the moment. Have been trying since 27May 2023 to get someone to assist me with redeeming my personal coupon code for travel but no-one responds to the emails (not services or ticketing). I just bought another air ticket too on Travelcheck! :( post purchase regret on that now! Don't use them, they don't respond post purchase anymore. They used to be great ...