Lancet accounts do not understand accounting

Lancet's accounts department is an absolute embarrassment for anyone that knows how accounting works. They compile one account with numerous accounts. There are credits in many of the individual accounts, and one or two small amounts outstanding on others. They harass me daily and hand me over weekly to pay the outstanding amounts of below R1000, however the other accounts are in credit with more than R1000. It is shocking that they can not either offset these, or contact me to refund me and then I can make payment on the outstanding accounts. SHOCKING! This is shameless harassment.