WORST ONLINE SHOP AND CUSTOMER SERVICE EVER!!!!

Worst customer service ever!!! Received a broken desktop computer, had it returned, the power cable was left behind, I offered to buy it, they said no and eventually a courier came and got it, 3 working days later they told me the package would only be delivered to them in another two days time. I told them I know they have an agreement with couriers that they have 3 working days/72 hours to deliver a package back to them... In the mean time I have received no refund/credit, in a week I have to travel and will not be able to collect another item for 3 weeks, not only this but I've lost other good deals becuase of them not doing their jobs...