RETURN/REFUND PROCESS

I am not happy with the return/refund process i am currently facing. i mistakenly bought a baby gate extension instead of the gate itself, which was delivery promptly. I called them on the 18th August (same day i received my order) and twice after that to return and they said they will send a courier, its now the 1st of September, they do not communicate at all unless I call, which is taken casually by the consultants each one saying we will notify you when they courier is available, meaning no courier has been working since the 18th August? its unacceptable.