Fixing API between Simpro and Craft ECommerce web site

We have an API link between Simpro & Craft, One of the links seems to not be updating - not sure why, also Im sure the Simpro API has more functionality - would like to get this linked also

Currently in Simpro we have code the Craft links onto (example below)
BRAND_COMENDA
BRAND_HOBART
BRAND_ESWOOD
BRAND_ECOMAX
BRAND_ELECTROLUX
BRAND_LAMBER
BRAND_WASHTECH
BRAND_WINTERHALTER
CATEGORY_PUMPS
SUBCATEGORY_SQUEEZE TUBE
PRICETRADE_$36.90
PRICERETAIL_$41.20

We have to manually update the price when it changes on Simpro -- this should be a API link and it is not