Complain about RCS Group

I paid my account via fnb app proof of payment was sent to them at 1st I was told it takes 5 days - after 5 days I went to Game mall of Africa to seek assistance and they contacted customer service and they advised me to email the proof of payment to *** and the response was proof of payment received and it will take 7-14 days for the payment to reflect. Collection department is useless and I was even told that they are doing me favor to request my payment to be allocated. All extra charges must be reversed because is not my fault that payment is taking this long to be allocated. This is the useless service I have ever received and it affects my credit score due to the poor service.