TFG not passing credit on item returned via courier

Just before lock down I purchased clothing online and could not return the incorrect items to a shop. TFG arranged a courier to come and collect the items in May 2020, without notifying me beforehand. I received a credit note for the items except for 1x jacket at R974.25 which was returned together with the other items in one box. After numerous e-mails, this still have not been credited nor have I received relevant feedback. The TFG person/s does not read my e-mails and then asks me when they can collect the item... I clearly explained that this was already collected but not credited. I have been a loyal TFG client and paid my account on time for over 15 years and this is the poor service I am getting, 5 months and this have not been resolved.