Stupidy online system

Please order #*** on 27 November for 3 Stoves. Stupidy system does not calculate the delivery charge while online. So, you have to pay for the goods first. Then the same day they send you an email with the amoutn to pay with a payment link. When you click that it shows the invoive that you have already paid and delivery R0. So how are you meant to pay for th edleivery? I phoned a few times all calls took over 30 minutes (meanseered on the phone app) but no response. Wrote to the on 28th November and again 29th November. Got a response on 30th stating how the delivery charge is calculated but nothing about how to pay it, That really does not help at all. Wrote again on 30th askign for an invoice so that I can pay. Still no response. Phone this morning and the operator cannot hear me. She says they have a backlog I must just wait. This is a stupidy system that has not been looked at to see how one pays the delivery and now I cannot find out where to pick the stoves up either for flats that were occupied yesterday. It is clear that this groups online purchasing has a lot to be desired and I will not use them due to this again. .