They cant give me my refund since yesterday

Hi this company works also with the municipalities and im in the Lekwa Teemane municipality christiana,,, I did ask them for a settlement letter and they first give me a wrong one to pay them and the second time they give me a right one...so i went on with the wrong settlement letter and pay them....now when I ask them for a refund because the amount wrong they dont want to give me....never trust this company....they fast to help you but they ****s...thats how i feel...stop this company