Cancelled flights no refunds or voucher offered. - basically theft

Had a booking with Comair, they cancelled 1 leg of the trip. They said they cannot refund the first leg as it's linked to the 2nd and that if we cancel we can get a refund on taxes only. The flight is legally allowed to fly as per government regulations but comair have cancelled all flights until 30 June...I assume as a means to ***** all clients money.

They only offered us a voucher for 3 months and said they are in business rescue they don't have to offer any refunds.