Bad service from Discovery Travel, Worst service

It has been two months since I cancelled my son flight ticket that I booked via Discovery Travel website. I have been waiting to get a full explanation as to what happened not my sons Flight refund, I cancelled his ticket and then mine a few days later. I didn't get a voucher for his cancellations, I cancelled my ticket a few days later (my ticket included my daughters ticket too) then I got a voucher for that transaction. Now discovery travel thinks they can put a wool over my eye and give me the voucher that is a refund for two tickets and think its for three tickets and expect me to be ok with no full explanation.