Charged a ridiculous fee for 1 extra box!

I requested a collection from Joburg to Witbank. Price given on website was R150 for next day service, as this was the cheapest option (road freight was more expensive). The collection point gave 2 boxes to courier. One was the same size as I request on the website, the other box was twice that size. MDS send me an email that the price increased from R150 to R577! I was very unhappy about this and send an email asking to inform me of where the parcels are so that I can collect it myself, as it wouldn't even cost that much to drive to Joburg! The parcels were however already on their way to Witbank. I send an email to Tanya Catlow, stating that the quote on the smaller box was R150 (which already included their petrol and other expenses from Joburg to Witbank). So I can't think that it is accurate to charge R577 just for an extra box! Tanya rep**** by saying: \I do hear what you are saying, however 2 rather large boxes were given to the driver. The service selected was out fastest service, being Next day Express to Witbank. We even delivered 2 day early.\" I only requested next day delivery because of the cheaper price given! I would have been happier waiting 2 days! VERY UNHAPPY!"