Cancellation and refund

Hi

I have been trying to cancel 2 orders i placed online and receive a refund however after calling their call centre on 4 different occasions i still haven't been assisted. Every single time i called the agents reassured me that its been cancelled and that i would receive and email to do a manual refund yet every time i call back the new person i speak to informs me that it hasn't been cancelled.. Does it have to be so difficult just to get a refund? This is really poor service!