False advertising re delivery time and bad responses from their customer services

I ordered an “e-table” stand for use in bed as i have just had spinal surgery and am confined to bed for long periods of time during my recovery. We ordered and paid gor it on monday 18 September and according to the website was promised 5-7 working days for delivery. On the payment confirmation 02 October was given as the delivery date. This is the confirmation they sent to me on 18th sept after payment was made: Order Number: ********** 1 Ordered on 2017-09-18 Hi Jonathan, Thank you, we've received your payment for order ********** 1. Your order is being processed and your estimated delivery date is Monday, 02 October 2017. Once your order is ready to be delivered, you will receive an SMS notification confirming your scheduled delivery date. Upon receiving this i wrote to them in consternation as when you subtract weekends and 25 sept (heritage day), 02 october is 9-10 working days from 18th September. I explained my frustration and health dilemma and requested they remedy the situation and deliver by the advertised dste. Since then i have had several unsatisfactory communications with them where they have insisted that the delivery date of 02 oct is correct and falls within 5-7 working days. It clearly doesn’t. In the latest response from them received on Saturday 23rd the only remedial action they were prepared to take was to cancel my order which is not helpful after i have already waited 5 days for it and desperately need it in order to function post-surgery.