incorrect billing

My mother purchased a bed two months ago and the price was R3999 ,when she checked her statement,there was R850delivery ,which she was told its a standard price for when they need to collect and redeliver if something breaks on the bed,mean while insurance is also on the statement so what is that for?the toatl amount to be paid is R16 000 ,wo this is such a ******* for a pensioner who they thought they will *******,she asked head office in cape town to call her ,they did the manager said they will rectify ,they never did she went to Lewis stores they took the statement and said she will be called by the store manager and they will fix this ,nothing thus far,the debit order will go off on 1st and still the statement is not correct I need someone to take ownership of this or collect the bed at no charge ,this is ridiculous and bad customer service and this is not the first customer to complain about the service there